The art in question looks like a pin-up poster you'd see on a WWII bomber. It looks like a classic charcoal drawing from the 1940's or 50's.
That's the kind of art you'd find in a mechanics garage in the old days, guys building dirt bikes.
Pin up art has more to do with Sailors being out at sea or a group of men up north in a lumber camp, the kinds of places where a man goes a long time, months or years without being in the company of a woman.
The clown face?
I looked up clowns on WIKIPEDIA, and By definition, the origin of clowns in history is interesting:
"... clowning is often considered an important part of training as a physical performance discipline, partly because tricky subject matter can be dealt with, but also because it requires a high level of risk and play in the performer.... Their entertainment style is generally designed to entertain large audiences..."
Melvins have always been into hybrid styles. The art itself is gaunt, a directly contrasting visual. It's almost like it's been defaced like Graffiti on a subway ad or something.
The heart with the Bullseye, that enhances the symbolism aspect of the piece itself because of it's more obvious legibility. Things in art can take on so many different meanings, like the skull and cross bones, and flies...when I think of flies as a symbolic representation, I think of something that feeds off death, you know? Beelzebub, lord of the flies.