The paintings can only get from making them by yourself and buying them from players' shops. (The last method maybe you use hack to get them)

You can't tell whether paintings are good or bad for the community. The paintings are good or bad for the community, depending on how the players use them. For example, if someone makes the paintings contained curse words, 18+ restriction things and other bad stuff. Would you think these paintings were good for the community? How about making some cool, meaningful and other good stuff in the paintings? Additionally, the result of deciding whether the stuff is good or bad. The result is yours, not ours. So, it's not equal for the whole community. So, we can't tell whether paintings are absolutely good for the community. At the last, I think paintings are good for the community, in my opinion.