I know the BRS girl normally does in fact wear a black string bikini top with a front tie, but can anyone actually see that bikini top in this image? It just looks like a cropped shirt and/or part of a cape here.

I think you're right. I don't see a bikini top and judging from the sleeves on her left shoulder, it must be like a torn off shirt.

I just noticed that she's got the flat chest tag, but she doesn't really look that flat to me.

needs to be pale.

Looks like she lost her bikini, and her sweatshirt-trench is just barely covering her bits.

"If Americans make Black Rock Shooter."