It's an interesting ethical dilemma, in my opinion, and one that has made me squirm more than once, though not in this case, for whatever reason.

There are real women who very definitely appear under age. Not prepubescent, to be sure, but definitely below the age of majority, and yet they most certainly are adults, regardless of how they appear.

I would classify the images I posted as a petite young woman, easily believable as a 19 year old as otherworlderotic.com represented their intent, but also believable as someone a few years younger, had they intended to represent her that age as well.

For artwork that can be interpreted equally believably either way, and is not intended as a depiction of a real life person, the only thing we have to go by is the intent of the artist, or in this case the intent of the prompt writer.

It would be a very different matter if the subject in the photos was not believable as an adult at all.