Can anyone explain this?

[Zellogi]

So it's not "a rather stale meme" as he was banned already, and it still happened.
Also I'm almost certain it's someone abusing PAC3 as I cannot think of anything else that lets you display actual pictures. E2 can set the material of props, but only to existing materials in the server's garry's mod directory; you can't use custom materials, so you can't display pornographic material with E2. And I looked through all the Wiremod components, and I found nothing that displays pictures. So it's either PAC3, or they know something I don't.