Originally Posted by
Manfred M
If males have narrow faces and females have round faces, okay.
The reasons are a bit more nuanced.
With broad lighting, the camera is pointed at the side of the face that the light is hitting. If the subject has a narrow face, the lighting illuminates a large part of the face, which makes it look larger. This tends to render a narrow face more attractive. The opposite is true for a round face. Light hitting the side we are taking the picture from will illuminate the face and side more and make a round face look rounder than it is. This is usually not desireable.
With short lighting, the camera is pointed at the side of the face opposite of where the light is hitting it, putting it partially in shadow. This has a slimming effect. This is the reason we don't want to use this technique on some with a narrow face. The shadow will make the face look even more narrow.