That mailbox is one of the type you can't pin down exactly. David Aber (who sent the photos on April 13th) saw it as a truck. When I saw it, the ladder reminded me first of a fire truck. (Also see the bulb on the roof: is it a flashing "emergency" light? There's another view in the photo below.) But, hmmmmm, could the curved bar above the wheels have something to do with a railroad caboose? Whatever: You can see that I obviously have too much time on my hands.;-)
Here's a view from the other side: