Muscle tone is what I would say is required of today’s supermodels. Women also have a layer of fat just below the skin that men don’t have, which helps to smooth out the features. Any extra fat is like a cancer to a supermodel. There is a fine balance which has to be maintained which involves workouts, diet, and natural good looks. Between starvation and fitness.
It was the blonde hair that attracted men. Actually in the 50’s that bleached blonde look was considered “cheap” — then Clairol came along and said “blondes have more fun” and it became popular.