What does it mean when a video with nudity is not 100% censored, such as when a yellow smiley face is TEMPORARILY covering woman’s butt?

Question

What’s the point of censoring nudity, if the smiley face is not covering every single frame-by-frame of nudity.  Obviously, I’m not referring to network television, as that’s grounds for fines by the FCC.  But what if a video with nudity is uploaded to YouTube, and a smiley face was placed on the nudity every now and then instead of the smiley making the video completely appropriate for children?

Answer 1

They're probably hiding a very specific PART of the butt that is only sometimes visible.  Maybe the woman's anus or pubic hair is visible in the original footage? 

I mean, I have no context here, so all I can do is guess.  YouTube's demonetization and rules are often enforced VERY arbitrarily and different creators react to that differently. 

Answer 2

They delete any videos with nudity off youtube now and it can get your account banned. Stuff that was fine there 5 years ago now gets you a violation. Same thing happened to Tumblr. Even mild side nudity that's not sexual gets deleted. Or fruit mistaken for breasts.