The strange part is why we don't have equally rich categories for Africans. Native Americans not having their categories makes sense since there are so few of them left today, so Africans are the only large group left out.
This is also coming from a perspective where I'm assuming that the audience for this algorithm (outside of academic consideration) would be westerners where white people tend to be the majority. In that case fetishization generally would only apply to racial minorities, due to the fact that the term seems to imply a sexually gratifying quality to the "uncommon". I add that, speaking as an Asian American, that it's not necessarily all that easy for most people to tell Chinese from Japanese from Koreans, whereas it's basically tautologically given that a blonde can be differentiated from a brunette since the terms are more strictly aesthetic rather than geographic.
On your point about Africans, I would extend it to both Latina and the fact that "Indian" seems to be a catch-all for any South Asians. Middle Easterners are also not represented (though this doesn't strike me as a thing where racial equality is necessarily desirable). However, this is where I think the data set is mostly responsible.
I think you're reading too much intent into 4 labels. From an American perspective, Japanese was the original--commercial, censored--"Asian" porn, "Chinese" is typically amateur uncensored, etc. I... won't elaborate further here, but there are stylistic differences that have nothing to do with race.
But also what will the next model, and successive models, that are trained on data from AI generate images, be like? It seems you could get an amplified or skewed model that is pretty far from reality. At least currently they are all trained on “real” images (granted some images are heavily edited or photoshopped). I can imagine that In the (not too distant) future most images will be generated and not “real”.
That said, it might be too early to speculate on models trained on the outputs of other models. This algorithm seems to benefit greatly from the post-DALLE 2 art-gen renaissance, but still has a number of oddities and uncanny outputs (noted in the rest of this thread) that I imagine are nearly unavoidable given how familiar the human form is. But certainly, if such decisions end up amplified in later work, or through widespread usage, then the consequences are more significant than, say, simply reflecting uncritically a skewed data set.
Even searching for other races shows predominantly Asian women in the results, its quite disturbing.
I'm not trying to be sanctimonious or overly moralizing, but half the tags I would associate with ethnicity are east Asian. And while I lean towards treating it as a mere curiosity, I think it's worth discussing as having unintended consequences and interesting implications at the very least.