His sister is holding what I can only guess is the towel he was wearing and they removed.
The picture itself is censored, but only barely, like they have a

They also have the uncensored image of course , and his sister (who first showed me the censored version of the picture, much to my friend's annoyance) told me that he hates it because he had just finished bathing too, and his willy is small enough in it that you could pass it off as a child'sz but my friend managed to change the topic before she could pull out the uncensored version too.