In my personal opinion, the main subject (windmill) is far removed from the central point of atention. The tree is the main character, which is fine, but both of them are totaly out of focus. I would have cropped out the house's roof, and the wire fence which is quite unatractive. Perhaps a better angle for the composition is required. I would try this picture again in order to improve rapidly for the following challenges.
Seems to me that the windmill should have been more prominant in a photo titled after it? The big, dark bush in front dominates the photo and the fence and hand rail are big attension getters. 6 Swash
I would have liked to see it a bit sharper. I know you can't sharpen a moving item like the windmill itself but the surrounding area is also blurring a bit.