Your post does seem further to suggest that you're not too clear on what satire is
That was your term, I used the term "amusement mechanism" - bit clunky, but what I meant was the way the joke is organised.
The same trick was used on a few Topman T-shirts awhile back (one asked what breed your girlfriend was, one was an apology for making a mistake ticksheet). I can see how the amusement mechanism works on them, so I can see how they would amuse, its just that - to me - they were not.
So I can also see how this Rape poster is "funny" - and I find it funny - but I can also see that if the boot was on the other foot it would not be at all funny, as the stereotype that it is lampooning - that any male is a potential rapist - is not a humorous assertion at all.