To set the image as your desktop wallpaper, right-click on the image and select "Set as Wallpaper".
If you haven't seen it before, this photomosaic features this image from 'Brotherly Love Part 2' (ep. 86) :
I essentially created this image, so please consider my hours and hours of work ... please do not alter this image, reproduce it, claim it as your own, or make it available on your website. If you have any queries regarding this, please contact me.