I wonder if there is some weird rule of the MPA (the group that gives out the G, PG, R, etc. ratings) that certain parts have to be covered for certain ratings, but doesn’t specify HOW they must be covered. Covering them therefore, even with a picture of what they are, even a very real one that can correctly be termed “prosthesis” can still preserve a PG-13 rating in what would otherwise be an R film if it showed the actor’s actual netherparts.