It's not so clear; not only is there porn that has meaning or even a message(think some fanfiction, or certain hentai manga), but erotic art sits in a strange position. Philosophers still argue about whether 'erotic art' is art, or whether it can be delineated from porn at all. Not to mention, there are contemporary (last five years) arguments for and against porn itself being art. You can make a reasonable case (i.e. one taken seriously by experts in the field) either way.
MAIDEN: You hateful octopus! Your sucking at the mouth of my womb makes me gasp for breath! Aah! yes… it’s…there!!! With the sucker, the sucker!! Inside, squiggle, squiggle, oooh! Oooh, good, oooh good! There, there! Theeeeere! Goood! Whew! Aah! Good, good, aaaaaaaaaah! Not yet! Until now it was I that men called an octopus! An octopus! Ooh! Whew! How are you able…!? Ooh! “yoyoyooh, saa… hicha hicha gucha gucha, yuchyuu chyu guzu guzu suu suuu….”