Twilight Sparkle grinned. It was a grin a few had seen in Ponyville before. The creepiness of how wide it seemed was ameliorated by the joy in her eyes.
"A Mimic Array... engraved on a bit! This is fantastic!"
*Redacted* blinked. "So what does it let you copy?"
"No, not like that, it's named for its creator, Mimic the Great and Powerful."
"Oh, one of Trixie's ancestors or something?" He winced under Twilight's glare.
"Regardless it's a very impressive feat. Usually this array would take up enough space to fill a town square in order to get every detail right." Twilight set the bit on the floor and lit her horn, causing bright purple light to limn the engraving. "Spectacular! There's no bleed-out at all! It must be painfully precise!"
"So... what's it do?"
"Well, Mimic used it herself for making artifacts, like her Wing harness or the Fabled Golden Shoes." Twilight levitated a saddle from a pile of random junk and a pair of normal bits. "Given sufficient power input and the right control... the possibilities are limitless." She concentrated and the bits seemed to flow into swirling loops of runes across the saddle. She frowned. "I'll need to get Rarity to help me not make it look stupid but..."
Twilight set the saddle on the ground, before she moved the Array into a heavy floor safe and spun the dial. She ten struggled into the saddle. A flash of magic later, and she was wearing a dress very much like what she wore to that one Gala. Another flash, and she was wearing her dress from her birthday.
"I think I got it." She squeed. "I actually used a Mimic array and it didn't blow up for once!"