Few morsels of food for thought. Rural Route or City Route? Makes a difference. Rural carriers are generally paid for the route not per hour. City carriers get paid per hour and will take the time to drop the package to the location. Could be a fill in as some others suggested.
Also it looks like a UPS or Fed Ex job to me. I know for fact that some UPS drivers will park a small package or parcel delivery in a mail box because of their numbers matrix. Fed Ex (especially home) will drop some of their shipments at my mailbox which is only 20 feet from my door by straight line or 35 feet via a walk around the fence and deck. The UPS guy will always put the package at the door. Same with mail carrier.