I was about ready to call this the worst episode of the show. Rarity being hoity-toity is the least enjoyable trope in the series, and it's the one thing that actually feels like "a show for little girls" with all the negative connotations that go with that (come to think of it, it doesn't help that she's also the only one interested in dating, but that's another topic). Having her be stuck-up and self-centered for half an episode with nothing else was downright oppressive. Things picked up when the rest of the crew showed up, but I don't think it was enough to save the episode. And it was a bit of a drama-block that nobody ended up caring that Rarity tried to flake out on Twilight's birthday. It wasn't out of character or anything, but there seemed to be some set-up for a confrontation, like Rarity's entire attitude that she needed to hide putting networking ahead of her friends, or the drawing of the fancified dress.