Careful with this one - can be slippery when wet. I suppose you what to know how to get it on the desktop now. Setting the background as your desktop wallpaper can be done in a number of ways. One way is to right click the desktop background below and then choose 'save target as...' (IE & Opera) or 'save link as...' (Firefox). Don't forget where you saved it though! Next goto your computers display control panel and set the background to the image you just saved.
Another way is when the full screen wallpaper has loaded, right click it and choose 'save image as...' or 'set as Desktop Background' or 'Set as Background'. You'll have a flash of inspiration when the time comes. I believe in you. In fact you probably already know. I'll button it now.
Return to wallpaper thumbnails.