VistArtXposed ...the 'Graphics' section is for royalty-free graphics uploaded for anyone/everyone to use as they see fit. It is very definitely NOT for 'copyrighted' works.
For Screenshots, ANYTHING goes, as long as wall images are sufficiently obscured to hinder their re-use as walls by someone dilligently extracting them from the screenshot..... AND there is no content within that is in breach of code of conduct....porn, warez, racial vilification, etc.
Something such as the Simpsons WB becomes an odd case in that the images used are abundantly 'in the wild' as fan-art and [as was the case with one approach by MS over another submission to WC] cannot be reasonably rejected/refused by us unless ALL equivalent image use is removed universally.
Matt Groening cannot successfully campaign for a specific item's removal in the face of all existing 'unchased' alleged breaches of copyright.
The only defence of copyright is/must be dilligent and universal by necessity. A precedent of failed defence [through indifference or otherwise] weakens all subsequent argument.
It is why I fundamentally dislike the dispensation of 'fan art' as an escape clause in 'copyright' as it [can] cloud ownership/protection.
In an 'ideal' world any and all use or imitation of an art or object of copyright would require consent.
But it doesn't, so the Western world is 'free' [mostly] to look at life as 'grey', not 'black and white'....