Info: People have been asking where was Rarity in this episode, and it seems she was in the script according to Faust. Here’s an screencap from her dA.
“She was still working on her costume, and perfectionist as she is, it wasn’t ready. (I forget what it was.) There was a whole sequence where Twilight brought Luna to Rarity’s for a makeover, hoping she could give Luna a “softer”, less intimidating look. Rarity freaked out about getting to dress up a Princess and over did it, covering her in the pinkiest pink princess get up ever. Luna disliked it and in taking it off, had a piece of the dress in her mouth. Pinkie showed up just at that moment and screamed that Nightmare Moon ate a princess and all the kids screamed and ran.”