This photo shows a portion of the grounds of the Alaska Yukon Pacific Exhibition taken at night. Electric light bulbs were just coming into wide use at this time, and the 1909 World's Fair was an opportunity to show them off.
Some silvering is visible on the dark photo.
There is also an Image 229 (229 - S.S. Potlatch) showing a ship that appears to be part of the "mosquito fleet" of passenger ferries that sailed Puget Sound in the early 20th century. Perhaps Otto reused the image number because no one would be interested in an A.Y.P.E. card after the exposition ended.