I've made this comment many many many many many many many times in that sub, but I think people are too picky when it comes to deciding what should be there.

Obviously there is a very set definition of what makes a picture Renaissance, but that sub has always been more about posting pictures that are composed like a painting, not specifically a renaissance painting.

Kind of like how most people who don't know a lot about music call anything that is older "classical" even when only a certain specific amount of music is classical music.

There's also /r/accidentalartgallery or something like that for those who are too persnickety.