Yeah, the angle and lighting of her unintentional face reveals are usually shit, that's why her face can look wildly different in each face reveal clips. To me, she looks well above average even in her most unflattering angles and conditions. She knows that she's hot and most of her viewers and gooners know that she's hot, both with and without mask.
At this point, I think she's keeping her mask on probably because she wants to maintain the remaining privacy that she still has and also because she wants to avoid any unwanted drama and stuff from twitter and the vtuber sphere because god knows that the people from those places are very sane and well adjusted. Although, it would be pretty funny if one day, she says fuck it and starts her Monday stream without mask on and just yap and stream as per usual without any prior notice or anything.