When women look at these ads, they are encouraged to see themselves as a man might see them. Such ads, as Paul Messaris puts it, "appear to imply a male point of view, even though the intended viewer is often a woman. So the women who look at these ads are being invited to identify both with the person being viewed and with an implicit, opposite-sex viewer."
I've often found this happening when I read the sex scenes in Mills and Boons (yeah, they have them; are you surprised?). The woman is always described as if she is being looked at by the man. Often, the most detailed descriptions of the woman happen when she has just met the Hero.
If one were to put it in cinematic terms, this would be an over-the-shoulder shot, where the codes of seeing are defined by the presence of the male in the frame.
Please to note the double gaze-making in the folowing scene from Love In The First Degree by Patricia Coughlin (admittedly, this is a Silhouette Sensation, and of a slightly more purple hue than M&Bs)
"Good. Then come here." He wound her nightgown around his hand to draw her closer, then pulled it from her grasp and tossed it aside. "You won't be needing that tonight."
Before Claire could react, he spun her around and backed her up against the wall opposite the closet. When he leaned into her she could sense the night's accumulation of fear and frustration simmering just beneath the surface of his desire, and how hard he was fighting for control.
The mirrored closet doors reflected the image of her slender frame pressed tightly to his broader, rangier body. She was stunned by the sight of them together, Luke looming over her, wearing a black t-shirt and faded jeans, while she was barely covered by the brightly flowered demi-bra and panties. The contrast was wildly erotic.
The rest of it is progressively more nauseating, but the important point here is that the woman in a cheap romance often sees herself through the eyes of the man. In fact, any sex that takes place is more a question of what is done to her, than what two people engage in mutually. Long descriptions of the woman's anatomy are usual. I had always found this more than a little puzzling, back in them days. Who wants to know, I used to think. But it is in precisely this filtering of desire through what supposedly turns a man on, in these books, that the erotic - such as it is - lies.
Or so we've been lead to believe, through not only these books, but also through advertising and other media.
Please read John Berger's Ways of Seeing.