Instagram stunt, obviously. The "point" being made is apparently that there is nothing inherently sexual about female bodies, or the pieces of clothing that cover them (or not), and that if people view a woman in a teeny tiny bra, suspenders, thong and stilettos as sexual, then this just shows what an awful misogynistic society we live in.
The woman in question was particularly scathing of anyone crying "what about the CHILDREN!!", because yes, children exist, but so does her arse.
I mean, I kind of get the argument. Of course women shouldn't be seen as primarily existing for the titillation/gratification of men. But, we live in a society with accepted rules around decency. Sex is normal, but I feel very strongly that we shouldn't be exposing our children to sexualised images, and I'm afraid I do see sexy underwear as sexual! Am I a closet misogynist?
I don't know how many people will agree with me/understand what I'm getting at, but you lot are always really good at putting my "I really don't agree with this, but I can't quite form a coherent argument" feelings into actual words!