This task was very straightforward. I saw the mailman leaving the street, grabbed my unicorn and my camera, and headed out to distract him. It turns out he had left the street and was preparing to drive his truck/van/vehicle away, but I caught him just in time to call out his name (Mister Maildude, of course) before he had driven away. He stopped his car/van/boat in the middle of the street and stared at me inquisitively until I ran over to him. He opened his door and I asked him if he wanted to pet my unicorn. He agreed and he pet her. I thanked him and success was mine. I distracted the mailman.