This was the first appearance of Angel, Beak, and Stacy X following their stint in New Warriors, where they were all de-powered. Beak and Angel appear without powers but Stacy X inexplicably has her mutant appearance back without explanation. Or she's wearing makeup/costume to appear like a mutant.

I think I remember from her episode of Cerebro that it was revealed that she was just using makeup, but text later in this issue implies that she still has her powers. Probably just an editorial oversight

Yeah I think you're right, it was a mistake and the makeup explanation was a light retcon/No Prize fix.

It’s the bat that makes beak recognizable really

The first appearance of America Chavez!