Is fanart fluff? Could something be done to make it not fluff if so?

What's the opinion on posting non-oc fanart? Is it considered fluff (which seems to currently have a negative stigma attached to it based off of my reading of previous threads)? Would more effort need to be put on the behalf of the poster before it's accepted (theme / several works from the same artist / some sort of comment showing analysis, reflection, or appreciation)?