Is the controversy regarding Miao Anna's exposure because her lower abdomen was slightly visible?

It wasn't even nipple exposure..
It wasn't even more than half showing; it looked like it showed slightly and then she realized it and fixed it herself...
I came here after seeing a "Tidoreee~" (sad sound effect) clip on Shorts, but is there something else going on?
It doesn't seem like a situation that would cause such a huge stir...