I know what it is, and I will speak it's name. No, it's not attempting to hide the skull coming out of her face. It's the ... get ready ... put on your knee pads and mouth guards. Ready? Are you sure? Life insurance up to date? I'm going to speak to unspeakable evil, you know! OK. You asked for it.
I was originally going to go with the physics of how those breasts actually exist in a 3D world, but that truly is unspeakable.