wallpaper should be scaled
Please describe the problem you are trying to solve
when creating a set of wallpapers from a set of images, Shotwell exports the images to its own place, but does not attempt to resize the wallpapers. as a result, wallpapers are often badly scaled
Other solutions you have considered
workaround: once Shotwell has loaded the next wallpaper, go to desktop and select the 'scale' option.
Shotwell 0.22.0 installed as part of Ubuntu 16