It reveals so much about Ironmouse and EN vtubers as a whole with how she answered this question. The correct response is "I am a pink haired demon mouse with horns" and you can deliver it as serious or as bantery as you like, but when you're on air you're that character, period.
>ugly, that's why I'm a vtuber
is her real feelings about herself and her projecting that same insecurity to all vtubers