Ok, I couldn't make up my mind what C2 depicted. I got the sense it was something along the lines of Pousin's The Shepherds of Arcadia
but I thought it also might be some type of depiction of cavemen drawing on a cave wall. Then I couldn't make out if it was a wall at all. It also appeared it might be some oversized hand, like from a statue ala Ozymandias, sticking up out of the ground. Giant hand made me think of The Monkey King pissing on Buddha's hand.
In the end, I decided to just work around it and leave it room to be whatever it was.
I mention it because now seeing it in level 3353 it now looks like it might be some kind of skull left in the woods. A dragon's skull maybe.