She's not talking about the regular big booty sista that's been around since the beginning of time.
I think she's speaking about the absurd, extreme exaggerations of the female image that some trans women promote.
I think there's a hint of truth to what she's saying but I don't think her examples of "prison culture" are correct.
I think this theory is adjacent to the one that a lot of women nowadays have borrowed a lot of makeup tips from
gays and drag queens and thus look like them. Now they're biting the ridiculous enhancements that some trans women do (Kardashians also).
I think Azealia is crazy as cat shyt but I kinda see what she's trying to say, sans the lowkey hate she threw in.