There is a bit of a false equivalence between entropy of output distributions and creativity here. Is diversity really the same as creativity?
It still might not be especially diverse if all 50 examples were from western European art. 500 years only takes us back to 1524 - not especially long and mostly from the same early modern period starting with the fall of Constantinople, the end of the Crusades, and the start of the Renaissance. I wouldn't be surprised if 80% or more of the works ended up being some depiction of aspects of Christianity painted by a white male.
Are you saying diversity in art is signified by the artist's race and sex?
Also, I have tried the first llama base model and while it was fun to interact with, I'm not sure how useful an "uncensored" (as some people likes to call it) LLM is for practical work. I think you could obtain better results using 4chan as a mechanical Turk service honestly.