Inspired by Jake Heritagu's Silent Ponyville series, I have written a beautiful nightmare for Rarity to endure. She will be facing the "Visage" - an entity that beckons her through the mirror, and into a world that holds a special interest in poor Rarity and her enviable beauty.

You can find his work here! http://jake-heritagu.deviantart.com/gallery/31046154

I make a few references to the original story (Pinkie Pie's, mainly), but it is intended as non-canon and essentially my own spin on things.