Sometimes 10% more of a desirable feature (man's broad shoulders?) or 10% less of an undesirable feature (woman's small nose?) is perceived as more attractive than the average feature. It only takes seconds to determine if someone is especially attractive (subconsciously would they make a good mate?). Also, many celebrities take very good care of their skin and bones (facials and workouts and strict diets) to preserve their 'investment' unless they are perhaps character actors needing a sinister or funny face, etc.