would someone explain why this is tagged with bad anatomy? because I really like the perspective she's drawn from.

I think it's mostly around the chest area. Proportions are acceptable, but her breasts are incorrectly attached to the rest of her body. Left shoulder is also a bit strange...

Yup, the breasts are up in the air like she's in the middle of a spinal disk shattering bounce, the near shoulder doesn't exist, and on a more minor note her hips aren't really attached to her spine properly due to trying to make them and her ass bigger.