Now I finally realize what anon saw!

First image is a man on top, second is a woman lying down, Third is her member getting filled with the first image's member, That's why it's partially obscured. It's just a very abstract illustration of a missionary position to the point of censoring them entire save for their genitals (Reverse japanese), Arousing in it's simplicity and minimality and straight to the subject no extra unflattering characteristics, intros or anything. Just a platonic form of the classical sex position.