Ugh. I HATE the way people just ignore all the specifics that go into the animator's model of the character!!

Elsa is not the smirky promo picture. She is not 'exactly the same as Rapunzel!' And she is not some doe eyed big lipped Barbie/bimbo doll. She is also specifically unlike Idina in the jawline and lips and not human at all in terms of her nose.

Elsa's face has many specific deviations from Anna which you could easily use to work backwards from Kristen Bell's face to determine what a human Elsa would look like. And everyone seems so determined to not ever even notice this.

Elsa's jaw and chin are more delicate and smaller - but she juts her chin forward and it is strong while Anna's longer chin slopes back like she has an underbite.

It appears that Frozen deliberately decided to not use the same features from Idina that they briefly animated in Enchanted. The nose was already not human, so this meant making the jawline and lips refer to a different face type.

Elsa is thin lipped and has a relatively small mouth. Her upper lip is very very thin with little to no curve -- this contrasts a great deal with Idina but also with the vast majority of artists depictions of 'sexy' Elsa. Some day when Idina is very old her lips might be as thin as Elsa's -- but she is not there now.

Elsa's jaw is slight and more angular than the norm - while Idina's is very strong and square.

Elsa's chin - although very short - is much stronger than Anna's. I think that this IS based on Idina - partially because the way Idina loosens her jaw to sing. They gave Elsa the same stubborn tilt to her chin so that they could be more realistic when they had Elsa sing.

Overall I think that Elsa's eyes, hair and chin are all quite a bit based on Idina. Because Elsa's hair is so over the top and blonde -- people are generally not noticing that Idina has incredibly fabulous hair. (Especially for a Broadway person) and that she really is a bit of a doe-eyed beauty.

I think the eye shape and size are much more like Idina's if you were to extrapolate them to a human face. Eye color can be done with contacts -- so that isn't the big defining thing to me.