Feel free to discuss the art of your conworlds and concultures here. Yes, even if, like me, you don't have the necessary talents or skills to produce convincing examples.
In my case, I haven't really thought about it that much. I have only decided that in my main conculture, Péchkizhénk, traditionally, the officially sanctioned painting style, at least in the early centuries, was basically a cross between 16th-to-19th century European photorealism and 20th century socialist realism, using the techniques of the former to depict the themes of the latter. That's because Péchkizhénk has a strong ideological commitment to glorifying manual work, the more menial the better; and because it was founded at a time when photorealistic paintings were still the hot new thing in visual art, and photography hadn't been invented yet.
I've also toyed with the idea of giving them a tradition of battle paintings that show battlefield injuries in all their gory detail.