Skin is depends on your origin, there is a study done on the effect of geography origin, tied with weather and geographically conditions on ethnic skin type.
Africans have darker skin tone to protect them from the harsh sun and weather in africa, Middle Eastern also have a thick layer of skin than the westerns to protect them from the weather, if you put a an african woman, a middle eastern and a white western woman under the sun same amount, the african woman would have less or may not even have any skin burn or skin damage, the middle eastern comes next and the white western woman will burn red. This is all dependent on the skin layer, hence thick.
There is something also about facial features but I cant remember them, like small eyes etc, height etc...i really cant remeber, i have to look it up.
And the reason why i believe that Arabs are obsessed with beauty, is because its essential component of their lives, its more like a tradition that carried on but has modernized...just like the japanese or chinese, i think mainly oriental cultures are focused on woman's beauty. however this notation has changed tremendously with globalization.
The saudi princess, i heard she is 36 , not sure.