I look at flowers all the time. I look at cars that attract my attention all the time. I look at athletes completing their skills all the time. It is normal to look and watch. We in the U.S. are a voyeuristic society with that being a learned behavior from the first day a child watches TV. Add the cinema and its grows further with the conditioning process.
If my mate did not look I would be worried about her. Just because I look at another female does not mean I look with lust or desire. I may just like the sculpted art form presented with fashion and etc. That does not mean the prescribed 'fashion model' either.
Sometimes the mix of colors or lines attract me. That occurs with architecture too where upon I have some training. I like the features of combining lines and contrast of colors. Simple enough in my mind that my mate may also have some such likes too.