“Come out of there, you silly filly!” Twilight said, nudging the mirror. It was tall, especially for her. Sunset was only four months older than her, but she was already using grown-up magic. In a few weeks, they'd both be Celestia's students, and then it'd be a proper race.
“What? Who said that?” Sunset asked, looking around and feigning confusion.
“I did! Over here!”
“Who’s there? All I can see is this mirror,” Sunset pulled a face of mock horror “...Are you my reflection? Am I the reflection?!”
“No, Sunset, we’re both real, and it’s almost time for lunch.”
“But every mirror has a whole world inside it, nameless spirit! How could we both be real?”
Twilight giggled. “It’s a one-way mirror, you goofball. Come on, I’m getting hungry!”
Sunset dropped the act and slumped. “Already? Fine.” Her horn sparked with magic while she closed her eyes, and then the mirror disappeared in a towering puff of orange smoke.
Then they trotted, side by side, towards reality.