Naturally, the show is about stuff caught on camera and this episode was on hoarding. For whatever reason, my mind thought "okay, maybe ponies will be in this one" (more like a collection) and sure enough, although not completely visible, what looked to be a Make Me Better Rarity doll was amongst the pile in one of the houses' rooms as it had a pink head with a horn and research appears to confirm my sighting:
http://mylittlewiki.org/wiki/File:MakeMeBetterRarity1.jpgIt's part-way through the episode, during the first (and 2nd sort of, though it's more of the resolution of that same story).