The shape of a female face that people find beautiful is similar in proportions to children and infants, which ALL of us are hard-wired to respond to in a positive way. In men's brain's, especially if there is a sexually provacative context, a chemical response is triggered that rewards the male just for looking. Het men also respond to "attractive" men's faces (just like everyone else), but it is more in terms of a dominance/submission response and does not tend to trigger the same kind of chemical response in the brain. Women get similar chemical responses and arousal triggers, but much less from visual stimulus than men. In general they seem to get the triggers from emotional context instead.