Basically, it's the (il)logical conclusion of the "why isn't there a WHITE history month/WHITE pride blahblahblah?" line of thought. The cartoonist is trying to point out a perceived double standard in race relations where blackness is celebrated and whiteness is vilified, "conveniently" forgetting that 1) his depiction of the little black girl/black dolls is racist as fuck, and 2) that little kids are more likely to assign special value to an object that stands out from other objects in its set (which is why kids will fight over who gets the red cup/purple toy car/yellow bucket/whatever).
