1. It is relatively easy to a knowledgeable photographer to make these women - or any women - look gorgeous on photos, even without photoshop or makeup, because photography is a matter of choosing a particular projection of a 3D object onto a 2D medium.
So one has to look at a lot of shots, esp. videos and snapshots / paparazzi shots, to see what these women actually look like in person.
Emily DiDonato, I would say, is the closest approximation of the Western ideal of beauty.
Bar Rafaeli, an otherwise top contender, isn't helped by her slightly low cheekbones, shape of the eyes and gums, and a slightly masculine face.
Doutzen Kroes: a very wide jawline and a plain-jane face. Take away fame, hype, hair/makeup, retouching and you'll see that in a major US city you can routinely pass by 5-10 girls looking like that and not even turn your head.
Joan Smalls: to me this girl is a younger and much, much, much less spoiled drop-in replacement for a Naomi Campbell. Pretty in her own right but see what I said about Doutzen
Song Hye Kyo: I can't judge her beauty as I am not attuned to the Asian standards of beauty (she looks very similar to me to dozens of other Asian models) and I am vehemently against as photographer to judge non-Caucasian talent based on how Caucasian they look - which is what a lot of people seem to be doing.