Only the sex in classical sense (penetration) is censored, so the rest is visible because technically speaking that is not sex (if we keep to the strict definition of sex).
This has got to be the strangest censor thing I've ever seen. Feeding her mouth black cock: OK; Spreading wet pussy lips: OK; Pumping cum into her mouth and in her face: OK; Fucking her in the butt: No we have to draw the line somewhere...