Short Depth of Field
With the hazy background, the short depth of field really accentuates the main figure in the composition. She is the main focus, making the photograph really strong. My eyes immediately went to the girl in the foreground instead of scanning the entire photograph.
Long depth of field
The long depth of field in this photograph gives us a sense of a story for the two women walking. As a viewer, we get to see more than just them close up. We get to see trees and a path as if they are walking through a park. The depth brings this photo to life.
The haze interferes with the long focus in the trees. There is depth but not long depth of field or focus. It is longer than the top example because there is relatively sharp focus from the bench to the women.