Commercial interests:

The competitive, market economy in which publications are produced, vying with each other for attention on the newsstand and for advertisers’ dollars, makes it clear to the viewer that the choice of imagery reflects a commercial decision to pander. The right reader is to be seduced (one who can afford the products advertised in the pages of the publication), a reason why so many magazines feature the same young, physically fit, upscale woman on their covers.

When working as picture editor of the New York Times Magazine I remember being told that we had to place more emphasis on our covers to compete visually with other publications (meaning more dramatic color and lighting) - even though the Magazine was sold as an insert of the Sunday newspaper.