I think it wasn't that exact image (that's been around since like the month the show premiered and was always really obviously fake), but a bunch of fake screencaps made by some European dude who'd previously made a Mewberty Star AU comic or something. Those fake screencaps featured stuff like Star and Tom sleeping in a bed together, Marco and Kelly, and Marco with the tainted Eclipsa contract hands. No links, sorry, but it's definitely out there somewhere.
It was obviously fake and lame just from the content of the shots (like Disney is going to let Star and Tom share a bed even if nothing sexual is going on) and wasn't worth discussing beyond the novelty of the guy faking some okayish-looking fake screenshots, but Cotugno bitched for some reason and he bitched back. Like she got pissed off about him misleading fans, for some reason, even though after new episodes premiere everyone will forget about those fakes anyway, and he was saying shit like she should be grateful he made those because on the fandom side the break between S3A and S3B was so creatively dead. It was stupid on both parts; I don't know why Sabrina got so made about but "actually you should be sucking my dick" was equally dumb.
I generally have nothing against Cotugno too.