This image is unsigned but has Otto's distinctive writing. It shows a decorated automobile passing by a review stand.
Otto took many photos of the Golden Potlatch parades held from 1911 to 1913; not all of them were signed. This postcard was mailed in 1911, so it shows the parade in 1911.
The black bars at the left and right side appear to be a framing problem; Otto might not have cropped the image enough when printing it.