Display your PhotoStream as your wallpaper or screensaver in Mac

You also have more than a few options when it comes to selecting photos to display as your screensaver or wallpaper for your desktop background.  You can choose any Aperture or iPhoto library, but you can also choose your iCloud Photo Stream, so you aren’t limited to picking images that are saved locally to your computer.  Simply set your source to your photo library and then select which album with your library you want to use.