
When we think of pin-ups we normally think of a poster, calendar or even the nose art of an old bomber. But pin ups clearly bleed into other areas such as advertising, fine arts, fashion... and romance novel covers.
Romance novels are about romantic attraction, and that includes an appreciation of each other's physical assets. But I note an interest shift in just what assets are typically on display. Pulp romances were long referred to as "bodice-rippers" for a reason. A typical romance cover focused on the female form--often the cleavage area. If a male figure was present they were often positioned behind the female and in such as way as to pull or tear the clothing away from the general booby area.

This raises, for me, a fairly obvious question. If the great majority of readers are female way did romance covers emphasise female flesh? The two main explanations would seem to be 1) the art and marketing was produced by men and so represents a male point of view, or 2) the female reader is more interested in how they look to men, than how men look. Alternatively it could be a different form of option two. If the reader is going to take on the point of view of the heroine, in many ways see what the heroine is like is more important than seeing the love interest. However exactly why most important thing to know about the protagonist is their breast size, I do not know.
In any case, browsing the shelves these days shows that there has been something of a reversal. The great majority of cover now show just the man, and large expanses of what is now called, glibly enough, man-titty. Maybe it is the shift in publishing so that the majority of editors and executives are women--or perhaps simply the increasing female freedom to ogle.
In either case, I am not complaining.