"It was a large room with a series of semi-circular tables (with many terminals) all arched around the far wall. A wall, I should mention, that was covered from floor to ceiling in monitors. On each monitor was a rotating view of hall ways, factories, and... what the hell was that room? In the centre of the monitors was one three times as large as any other. There was something about it that was enchanting, and it seems Flare and Serenity thought so as well as we all moved closer to get a better look. Even with the threat of death by vaporization I had to see.

The large room in the screen seemed to be in a strange shape, with sixteen different walls, each the same length, making it a strange shape (I could only see half the room, so I guessed). On each of the walls, I could see a number painted, encircled with strange runes. The floor was covered in a mosaic of a white so pure it made the rest of the facility look dirty, and in a pattern so strange and arcane I couldn't make head or tail of it. In the centre of the chamber there was a empty space without tiles, dyed a deep blue. It was just large enough for a pony.

“What the shit?!” Flare gasped.

A pony that wasn't there before appeared. It was pure white like the tiles, and lacking a mane or tail. Something about the pony made my shoulder ache.

The pony flickered.

One second it was lying down. The next it was standing, its back to the camera.

“Is that really... there?” Serenity asked in a hushed tone, as if she was afraid the thing could hear us through the screen. But how could it?

There was a rush of wind. Something creaked.

The pony’s head turned all the way around. It stared into my soul with pits of fire for eyes."

Snippit from Fallout Equestria: Heroes. https://www.fimfiction.net/story/662/19/fallout-equestria-heroes/chapter-18-so-says-the-mirror

Commission for a friend!