Thinking more about how everything went down, it does make quite a bit of sense. The whole "girls' night out" thing is supposed to be an emotional boost. Beeps wanted them to be able to be their hottest, consume some questionable data (booze), and, for a few brief hours, be (along with Roko and the others) be unstoppable forces. But, particularly with *that* dress, the thought of getting tarted up a little was a major trigger for Roko's dysphoria. No matter how "hot" she looks to others, any attention to her looks, even her own just makes her more of aware of what she normally suppresses.