A very interesting subject. America has been trying to define "what is porn" for years. Phtrases ranging from" I can't explain it, but I know it when I see it" and "sexual imagery with no artistic or social merit" have been batted about, as well as a zillion other viewpoints and positions. In Utah, where I live, a poll was taken on the subject, and a measurable portion of the populace here consider Michelangelo's statue of David to be pornographic.
That is an an extreme and unfathomably ignorant position, of course, but it exists, nontheless.
What it illustrates is that the term "pornography", is subjective, and really doesn't mean anything specific. Something that has artistic value and relevance, can't be pornographic, by my way of thinking. It could be sexually graphic, obviously not approprate for children, or those with immature concepts regarding the human body(see above) But not porn. Thats my subjective opinion.