"There's evidence of organic matter that has decayed over the years, we traced back through our archives of which microorganisms broke down biological matter and their waste products, to determine the origins, but the results were unsettling."
"It was semen wasn't it?"
"...it was."
"And the sculpture inside?"
"...These ancient people had rather niche tastes"
From this wiki page, his style was built out of necessity, where he could only paint on a break, in effect he was one of the first speedpainters to become widely known (pulling that out of my ass because art history is something I know <1 about(slightly more than nothing).)