I chose this as my best image because I think it has a lot of elements that make it very dynamic. The way that the bridge intersects with the branch makes an allegory for the man-made vs. the organic elements since the branch mimics the direction of the bridge. The little leaves of the tree mimic the shapes of the steel structure of the bridge, which make for an interesting composition. Another point of contrast is the lively green and the blues and grays of the rest of the image. They provide a background for the branch to stand out.
The shallow depth of field is exhibited in the way that the branch, which is closer to the camera is in focus while the bridge and the skyline behind it are out of focus and very soft. I like that the image also has three levels of perspective, from closest to farthest. The closest being the branch as the foreground, the bridge as the middle ground, and the skyline as the background.