This is an important image because it clearly shows the blast pattern of the explosive which was placed in front of the fence beside the mailbox, as you can see by the locations of the fence and other debris just after the blast. There is no question where the detonation took place. In fact, a bystander has recently given an interview claiming his life was saved by the mailbox. If the bomb had been place behind the fence and behind the mailbox on the sidewalk, no bystanders could make that claim, only runners.