The "Posten" is a stationary traffic policeman standing in some kind of "bin" to regulate car and pedestrian traffic. The drunken gentleman (shawl, gloves, coat) clinging to the lightpole has lost his tophat at the other side of the street and yells for the "Posten" either to fetch him the hat or to block the traffic to give free way for him to get the hat by himself - what must turn out to be difficult in view of his condition
The funny point is the total disrespect towards this policeman, especially during war-time Germany. I´m qiute sure this cartoon refers to a real incident or situation
I hope this helps
Roland