This is a photo of the 1909 World's Fair held in Seattle, the Alaska Yukon Pacific Exposition. It shows an exhibit hall prior to the opening of the fair, when only Frank Nowell, the official photographer, was allowed to take photos there.
This image is a cropped version of Image X16 (X16 - End of Agriculture Bldg A.Y.P.E. Seattle 1909).
There are three other images numbered 22:
Reuse of image numbers and different image series make it difficult to know how many images Otto published.