I propose the synecdoche:
a figure of speech by which a part is put for the whole (as fifty sail for fifty ships), the whole for a part (as society for high society), the species for the genus (as cutthroat for assassin), the genus for the species (as a creature for a man), or the name of the material for the thing made (as boards for stage).
People who refer to women using 'vagina' or, more commonly, its obscene equivalents are employing the literary device known as the synecdoche. To refer to women as skirts, however, is not a synecdoche but a metonym. The graphic is an example of a visual synecdoche.
Time was, when feminists protested the objectification of women, and rightly so. Nowadays they self-objectify, presumably in the belief that by co-opting 'pussy' and other derogatory words they can remove their sting.