I recently overheard a conversation between a colleague and a student, both female, analyzing the cultural subtext of women's fashion advertising. They were discussing how lingerie and swimsuit ads usually feature models in sexy and tantalizing poses. One comment was that they usually place these ads out-of-doors, on a dock, on the beach, standing by the shore of a Norwegian fjord, in the woods next to a tent. The other commented that they do that to make it not seem so pornographic, to take away from the lasciviousness of the image (text).
I think that might be one reason. However, as a man, someone who is visually drawn to these images when my eye catches them (think Skyy Vodka ads in every magazine), I have to say that these locations satisfy the commonality of the male sexual fantasy realm. Every man, I'd imagine, has fantasies about having sex out-of-doors, on a dock, on the beach, standing by the shore of a Norwegian fjord, in the woods next to a tent, in the actual tent, on the hood of a car, in the back seat of the car, in the front seat of the car, halfway between the front and back seats; if it's an old Cadillac, perhaps even in the trunk. My point being that these images, that use eroticism to sell products, are always pornographic, and usually seek both to downplay the overt sexuality of the image and to fill the fantasy space common to as many people as possible.
I don't see how putting a vamping twentysomething in a bikini, outside, with the goods titillatingly close to being on full display is ever not pornographic. On a bed, in a bathroom stall, or sitting in a church pew, the image of a woman in lingerie, especially a tan, thin, chesty one, will always get attention, nay command it, and will forevermore be the object of the gaze, the longing one at that, of the Other.