That one isn't a line drawing, its a shadow relief drawing with depth removed. Then with with outlines applied to the shadows. Even then, the only reason why i

That one isn't a line drawing, its a shadow relief drawing with depth removed. Then with with outlines applied to the shadows. Even then, the only reason why its so "confusing" to us is because they applied some kind of random black shape to the background which extends above his head to the left. The black background blends with the man's body making an amorphous blob. If it was removed you'd be able to instantly tell thats a bald mans head. You are correct about the "line art rules" they're all just basic visual rules that the brain uses that artists have been playing with for 100s of years. Its no different than those illusions that look like a Grandma or young woman at the same time. All it takes is one conspicuously placed shape and your whole perspective can be thrown off. No different from how camo works: https://en.wikipedia.org/wiki/Disruptive_coloration https://en.wikipedia.org/wiki/Disruptive_coloration Anyway, my point being, this isn't some new phenomenon, its a well understood at this point.