Some photos are indeed taken with the intent of showing them to a female audience. The result is often a guy in an awkward position, sporting half an erection with a goofy grin on his face. Look at what mainstream men are popular. Nine out of 10 women would be very interested in seeing Russell Crow, or his type, naked.
Women fantasize about many, many different types of men.
Women like to view all sorts of naked bodies. Sexual attraction for many women is not just about simply viewing a naked man. The context of the picture adds to the sexual intrigue. We humans like to have a story or theme surrounding the picture. Don't forget that the biggest sex organ is the brain.