I love this! Not only is the model perfect for the shot but I get a really good sense of contrast. The simply clad woman vs. The complex-looking naturalistic background, the light of her skin vs. the dark of the sky and field, and (my favorite) is how clear and in focus she is while the background blurs.
Sorry to ramble. @_@ One more thing, though- I have to point out how much I love the motion in this picture. (Like, how she seems to be running and in the wind even though her pose is so solid).