In pictures models usually have a typical behavior.
Females avert her eyes and thereby shows modesty, patience and a lack of interest in anything else. Or stares straight at the viewer thereby becoming in the viewers ”control”
Males look off/up and thereby shows a suggestion of interest in something else than the viewer.
This is also show by statistics on profile pictures that Okcupid had done on their community.

”Stereotypical notions of masculinity are strongly oriented towards the active.” They avoid being feminine in not being portrayed as the passive object of an active gaze. They control and dominate the situation by making a choice of who to look out at from inside a picture.

Thus to change the objectification of women they need to start gazing more at men and thereby taking control, also when in a picture women need to focus on something outside the lens. The opposite applies to men: act mysterious but maintain the suggestion of interest in the viewer when portrayed in a picture.

So an inquiry to the females (for the sake of equality): GAZE MORE AT MEN;)

Source used: Notes on the Gaze – Daniel Chandler