You should look up what a communications class is.
Unless it was a communication class having to do with television history, sitcoms or something like that, and they were covering the Brady Bunch where the line was (probably, or at least popularly) derived from (albeit having to do with imagining everone in their underwear as opposed to being naked), this wallop of a "Clarification for Lefty" is in need of a little clarification for the one who wrote the erroneous caption.
I have no idea why everytime somebody tries to swing the gray stuff like it was a ginormous nutsack and make a big announcement about it always misses really bad unless catching the end of the swing with the back of the head was actually the actual intention.