It is possible to tell a fair bit about how a pony has changed, by examining how their room has changed. Some of these changes are easy to interpret.
Today, the window was already open, but even if it had not been the first noticeable was that almost everything in the room was bigger.
The bed was bigger (and no less crumpled), the desk was higher and wider (and no less messy) - one could assume that the occupant themselves was larger. The chest of drawers had been replaced with a narrow but high wardrobe, suggesting a greater interest in the world of fashion. The mirror had been moved slightly to accommodate this new furniture but was otherwise unchanged - it would be large enough for the Princesses themselves, and needed no replacing.
The old record player was no longer on the desk, having been replaced with a more modern piece of equipment requiring magic to function, sitting in the corner. The single shelf bookcase had been replaced with one that reached nearly the ceiling, filled with titles both book and musical, and was clearly very well stocked. The top shelf held a collection of dolls, plush figures and statues looking over the room, among them a somewhat worn-looking yellow pegasus with a short-cropped tail.
Naturally, the larger furniture took up significantly more real estate on the walls, but if anything there was even more pinned up than previously, despite the lower available space. It was impossible to tell what colour the walls behind were, for the images overlapped over each other and covered up to the ceiling, and were beginning to encroach onto the ceiling as well.
A viewer would be hard-pressed to find many familiar pictures amongst the chaos - a few still remained, although they were often far from their original positions. The banner with her name still hangs proudly above the bed, and although the passage of time has faded the crispness of its colours slightly, it is still one of the most impressive pieces on the wall. In the bottom corner of the banner, well away from the artwork of the name, a new addition could be easily spotted - a series of five musical notes, a triplet and pair of quavers, in mostly ascending order except a slight drop in the fourth, in sharp black against the banner.
While previously there had been no true pattern to what made it up to be displayed, one could now sort the majority of the images into one of three categories - elaborate dresses, musicians (frequently in elaborate dresses), and photographs in various locations, the majority of them including a familiar filly, now grown into a young mare, posing cheerfully with various other ponies. The five musical note symbol could be seen sketched and poking out behind other images here and there, and in one or two pictures was noticable on the flank of Crystal Chime.
Very noticable, in fact, as she slammed the door open, stormed inside, slammed it shut behind her again. Barely even glancing to either side, she dove straight onto her bed in an angry flop, letting out a somewhat unladylike grunt as she did. Her pillow was soon wrapped in her magic, pulled over roughly to her muzzle, and then she screamed into it, louder and longer than anyone might expect might come from a creature her size, even muffled.
When her lungs finally gave way, she lay there, nose still buried in the pillow as she caught her breath, panting heavily but otherwise not moving for several minutes. Evidently she eventually got sick of this, for she thrust herself up suddenly, slamming her hooves down then having to take a moment to keep balance on the bed's soft surface.
Leaping down from the bed, she moved over to the bookcase like she planned to run it down if it didn't give way to her, whipping her eyes over the selection of records before yanking one out with her magic, whipping it from the cover and onto the player with the speed and grace that comes from long practice. A quick spell later and the machine whirred to life, and moments later the music started to play, beginning with a strong minor blues descent that repeated, building up quickly as more instruments added themselves to the mix.
As the lyrics started, she added her voice to them, overpowering the album effortlessly as she threw her full vocal power into the song, every note hit spot-on and cleanly, just like her name might suggest. She closed her eyes, trying to let herself drown in the music, expressing her special talent to its fullest.
She got about two lines and a half lines in before she couldn't take it anymore, her voice going from singing at full strength to a degrading growl as she gave up, hanging her head and tail low, letting the song go through to the end of the verse before it began to irritate her further, flicking a pulse of magic at the machine with a twitch of her horn, causing the music to scratch out for half a second before the needle came off the record.
She couldn't concentrate on her music right now, not with what had happened that day.
Not useful... not useful my flank... hah.
For a while she moped around her room, looking for something, anything, to take her mind off what had been said that morning. She opened books, and got a few lines into each one before slipping them back on the shelves. She looked over her pictures, getting a few moments of contemplative happiness there, but even with every surface covered with them there weren't enough to keep her distracted forever by themselves. She sorted through her dresses, though she couldn't have said what she was looking for. Several times she started her vocal exercises, but just didn't have the motivation to get all the way through them before it just started frustrating her all over again.
Eventually she found herself in front of the mirror. It was a silly habit of hers she'd picked up when she was a filly. She'd imagined once that her reflection had come to life and helped her out when she needed it, but that was kinda silly. Still, she found sometimes it helped to talk her issues out with herself, effectively. It wasn't like anyone else could hear her while she was in her room - the spells that kept her singing contained in her bedroom could keep her personal life safe just as well.
She looked herself over in the mirror. She'd grown fast in the last couple of years since she'd gotten her cutie mark, with slightly awkward lanky legs that the colts occasionally teased her about - although a couple of her friends assured her that they only did that because they were trying to make excuses for staring at them. Her coat had darkened a little since she was a filly, and was a strange thundercloud shade that might be called grey, purple or blue depending on the light it was in. A coat like hers that was a single unbroken shade over her whole body was considered desirable among unicorns, but she found it ironic that nobody could agree exactly what that shade was.
Her mane and tail were wild messes that her mother endlessly chided her to tame, but she preferred it that way; her eyes a deep sapphire blue. Her storm-and-sky colour scheme was more suited to pegasi than unicorns, perhaps, but she'd never minded that. No, what drew her attention at the moment was what was inscribed on her side. She twisted slightly, flicking her mane slightly to get it out of the way, and examined the series of notes on her side - notes she had been so ecstatic to see the first time they had appeared, a five-note riff she had hummed to herself so many times since they appeared she didn't even notice she was doing it anymore.
Notes that that apple-flanked farmgirl at school had had the, the audacity to call...
"Not useful." She repeated out loud, rolling each syllable around her mouth. For a moment, it seemed that would be all, then Mt Crystal Chime erupted in a burst of indignation.
"NOT USEFUL? How dare she? How DARE she! Just because she happens to be an earth pony who grows food for a living, she thinks she can just go around putting down other special talents because they don't... they don't put food on tables?"
She seethed wildly, her vocal training and talent clear as her anger rose higher and higher, her fur standing on end as she paced back and forth in front of the mirror, the symbolic melody taunting her every time she turned. She yelled at her reflection as if it would magically fix everything.
"Guess what? I don't get to choose what mark appears on my flank! I don't have a family tradition spanning back generation after generation after generation! But even if I did get to choose I wouldn't have chosen any differently! I love music! I don't CARE if you don't think it's USEFUL. It makes ponies happy! It makes ME happy! It's fun and it's awesome and... and you can just go CHOKE on your apples if you love them so much! Just because you can put them on the table and see how much work you've done doesn't mean you can... you can..."
She trailed off suddenly, completely losing her train of thought, when she realised her reflection hadn't been ranting along with her for the last few vitriol-filled shrieks.
It watched her with a patient look on its - on HER face - as if wanting to be sure she was finished before it started. Her fur stayed on end, but no longer due to anger and aggressiveness, as her reflection spoke in her voice.
"If she got to choose, maybe she would have chosen differently."
She ran up to the mirror, pressing her face and hooves against it, staring straight into the eyes of her counterpart, who still seemed to be forced to mirror her body in full except for her face. "Celestia's mane. You're real. I thought I just imagined you before. You're real."
"Aren't there more important matters at hoof?" her reflection replied, its voice slightly strained, muffled by the glass pressed up against her snout.
"What. Oh. No! You're real! My reflection is talking to me!"
"And maybe you should listen to what it's saying. Why do you think she lashed out at you like that? Why she said that?"
"I don't know! I didn't do anything to her!"
"Didn't you?"
"No! We were just talking about how we got our cutie marks, and suddenly she turns around and yells at me that my talent is Not Useful. Like I'm a drain on Equestria just by existing! That's such a typical earth pony thing to say, feeling like they're so much more special to how everything works than us unicorns!"
"You don't really mean that." Her reflection's voice was flat and hard, making her flinch.
"I... well, I... where does she get off saying that sort of thing to me, huh?"
"Well, think about it from her point of view. How many ponies have special talents in music in your class?"
"Just me, duh! It's frustrating as all hell, I can never get anyone to jam with."
"And how many have apple marks?"
"Well, there's like... four of them. There's a lot of Apple family in these parts. You know them, they get around ever-- eep." she cut off at the withering glare her reflection was giving her, feeling like a foal caught swearing.
"She's surrounded by apples everywhere she goes. Everyone she lives with has an apple mark. Most of the ponies she plays with have apple marks. One of her teachers has an apple mark! She looks back, and thinks no matter what happened, I was always going to have apples on my flank. And then she talks to this unicorn who's gushing about a special talent that nobody in her family has ever had before, how her family is really supportive of her branching out into new fields, how she's really excited about it..."
"Are you trying to tell me she's jealous?"
"Is it that hard to believe? Maybe she would like the idea of being a musician."
"It didn't sound like it. She sounded pretty down on it when she said it wasn't useful."
"Just like you meant every word when you told her that you bet every apple she ever bucked fell down rotten, huh?"
"I..." She desperately searched for a comeback, and came back with nothing. "I really said that, didn't I?"
"And you can just imagine her sitting in her room just like you. She probably doesn't even realise how much she hurt you with her words - just like you didn't realise how badly you hurt her. And then tomorrow, you both go to school, and you barb each other some more, and soon you won't even remember why you started, you'll just hate each other."
It really didn't take any imagination to see it happening. "...So... what should I do?"
"Stop it before it starts. Apologise for what you said. Be the bigger mare. Just... show her you're happy to care about her. And her problems."
"I... I think I can do that." She was surprised to realise. It... it didn't even sound that hard.
"And if you really want to show you care about her... help her shine. See if you can convince her to take up music. I think she'd like that. She's holed up having to be one of a hundred apples, all the same - maybe you can help her break out of that. You'll have a friend for life if it works."
"...Are you sure you're my reflection?" Crystal put forward suddenly, grinning wryly. Her mirror counterpart blinked.
"What?"
"I could never think of that. There's no way I'm that smart. Or that nice."
Her reflection smiled widely. "You'd be surprised what you're capable of. On both counts."
"Huh. Well, if I can't believe myself, who can I believe? Thanks. I better figure out how I'm gonna do this. I wonder what sort of music she likes? Probably country, they always love country mu--"
She paused, realising she was delving into stereotyping the apples again, but her mirror image was following her perfectly once again, apparently having nothing more to say on the matter.
She shrugged softly, moving to her record shelf and muttering as she started picking out a selection of records, but constantly glancing at the mirror out of the corner of her eye as she did. She never caught it doing anything out of the ordinary, however, and was forced to stop when the time came for dinner, and she left the room with a bounce in her step and a five-note tune on her tongue, closing the door softly behind her.