This is truly talent my friend!
Nice, clean and crispy.
The background light makes for a nice gradient, and i like that you have used blue. This enhance the crisp, clean feeling.

There are not much errors in this picture. So its hard to find any constructive critique. If I shall point out one, it would be that I think you have just a little too much shadow under the nose. By looking in here eyes, it seems that the soft box is placed fairly high. Maybe you could have eliminated some of the shadows by lowering it. The easiest way of course, is to tweak it in PS This is not an error that ruins the image though.

The colors of here skin is warm and makes a great contrast to the blue.

The eye makes for a good attention drawer. Maybe you could have made them just a little more blue.

But with that said, i really admire your work here
This easily could have passed as a front page for a magazine!

Cheers from *mangatobbey

I couldn't stop myself from having a look at the portfolio of Grant Thomas both here and at M.Mayhem and wow.. Man, I can only say I had half of your talent at twice your age.

But to come back to the picture, let's start with the technical aspect first.
In short, this picture is perfect. Razor sharp where it should be, lovely diffused high key light, just about the proper amount of kicker light where I would like to see it. Also the smooth gradient in the background, the proper amount of light in the eyes.. There seems to be no piece of the frame which has not been thoroughly studied. Great, great job and very good post production too. It's clear, crisp and natural at the same time.

And as for the expression, I can only say I've been hypnotised. Eye contact is tremendously strong and what happenes with her mouth is what really makes this image. I can almost see this face coming out of the frame.