Certain artists seem to think that breasts are like beanbags, and they offer near-zero resistance to any kind of molding into any sort of shapes without any sort of pain.
Certainly not the first time anime artists have taken liberties with body parts and how they function. But then again that is not limited to anime artists, quite a few different kinds of artists have done the same with various media.
I get the feeling the flagger reflagged this picture after they failed to get it deleted. :/
They can't do that. They can get someone they know to re-flag it with a slightly different flag to around the double flag rule but they themselves can't reflag.