BBL's tend to work better on girls who have naturally big asses, it's why Mika's BBL doesn't look god awful. Similar to Violet Myers, she also ended up getting BBL work done but had a fairly decent ass beforehand.
But yeah, it's night and day compared to what she looked like before. Mika went from an awkward, emo Latina into voluptuous goth egirl overnight. Though she still acts awkward in her videos, that aint changed.