It’s a reference to 1 man 1 jar, a shock video that went viral about years ago.
Essentially, it shows a naked man squatting on a jar, which slides all the way up his ass. The jar then shatters, and the rest of the video is him trying to pull the glass shards out while clearly losing a lot of blood.
Feel free to seek it out if you are curious, but be aware you will see exactly what I described.
Oh buddy... that's the new, less horrifying shock content.
Lets just say that glass jars are not appropriate anal toys, there's a reason why glass sex toys are solid, and that some people have terrifying amounts of pain tolerance.
And this poster is an incredibly un-subtle recreation of the first frames of that horror. At least they added pants. And a lid.