Erotic or pornographic?

You can't define the undefinable.

Every definition is merely an opinion and as such has no merit to anyone else.

It still is undefined legally. And is a moving target. Legally it is still defined by "community standards", and that varies by community. (see Mapplethorpe)

Arguing it is like debating religion, and it pros and cons usually are stated from a religions perspective which is why the US still has such is such a prudish standards.

The number one arguments goes something like "we're trying to protect the children" who supposedly would turn to a world of crime and debauchery if they viewed a naked body.

An old and over used definition is, " if you use a feather it's erotic and if you use the whole chicken, it's pornographic".