I was thinking of this thread the other day. What if you took the opposite? Someone who's really ugly performing?
I would think they'd be judged on their performance. It's good, it gets more exposure (no play on pervious [what a typo. I' m leaving it.] things there). The same thing would happen though. At some level, the visuals would distract. In the "ugly" case though, people would thinking, "Yes, that makes sense that she's that good because... Well, look at her. She's not doing anything else."