This untitled image shows a trolley with "Alki Point" in the destination box and a "Luna Park" sign down below. We don't know the names of any of the people in the picture.
The grey area in the lower right corner is where part of the postcard was torn off.
A modern publisher, Lantern Press, now sells a copy of the image:
The copyright on the original has expired, so this is legal. We don't know why Lantern Press cropped Otto's signature, however.