Woodsy's right about the visual distortions... Everyone needs to go back and watch their favorite movie again to remember how hard it is to really see a hard image of a True Form Nazgul!
That being said, here's the classic Wiki shot with the face we are all familiar with.
(It looks more like Weta's sculpt, and they know the actor personally, designed his makeup and filmed him, correct?)
Also, aside from the list of "discrepencies" that Fritz pointed out, I'd like to add that the crown's spikes are obviously too short and that also makes the face look fatter than it should be.
It doesn't look realistic like the Gandalf bust or even the M. Lord- it looks like an animaquette. And although this whole collecting thing is based on personal preference, (some liking this sculpt better) I think the majority had their hopes pinned on a larger version of the Weta bust.
I know I did.
And I now correct my previous observation:
To me this bust looks like Gary Busey playing the role of PruneFace in Dick Tracy!
(I can't find a good Pruney screen cap, though. Somebody help?)