Supreme Court justice Potter Stewart famously stated, regarding hard-core pornography, during the Jacobellis vs Ohio obscenity case (1964):

I shall not today attempt further to define the kinds of material I
understand to be embraced within that shorthand description; and
perhaps I could never succeed in intelligibly doing so.  But I know it when I see it, and the motion picture involved in this case is not that.

In today's edition of Nature, researcher Nicholas Conard reports what may be the oldest existing example of figurative art dating to at least 35,000 years ago.  The sculpture in question, with its exaggerated secondary sexual characteristics (i.e., large breasts and vulva) represents the Venus figurines, which were common across Europe 20,000-25,000 years ago.     

Whether the sculpture was intended for ritualistic use, pornography, or simply reflects more relaxed social mores is open to individual interpretation at this point.  Your thoughts? 

That, of course, did not stop Science ("The Earliest Pornography?") or Nature ("Prehistoric Pin Up") from going for the titillating title.  Or yours truly, for that matter.  Hey, if it works it works.  Not our fault y'all are predictable.

It does seem, however, that the penchant for unrealistic depictions of the female form has not changed much over the millennia, let alone the last 50 years.