She would take these comments as compliments. She's aiming for skin and bones.
It's funny, she does look like that here. But I was thinking that in the other red carpet pics, her stomach looks wider than she lets on in that one Twitter pic. For the first time in her life, she actually understood a flattering angle (well, flattering if you like really skinny).
It's just all a wide middle, with no real shape. Which again suggests to me that she's just starving herself, and trying to work against her own natural genetics. It's flat, but wide. Kind of like what people always complain about with Kate Upton (who is still naturally very gorgeous, and has some curves).
Obvously her stomach looks pretty flat in the red carpet pics, but it's still kind of wide.