Careful with this one - can be slippery when wet. I suppose you what to know how to get it on the desktop now. Getting the wallpaper onto your desktop background can be done in a number of ways. You can either right click background wallpaper below and then click 'save target as...' (IE & Opera) or 'save link as...' (Firefox). Please remember where you save it to!Then set the desktop background using your computers OS's desktop or display control panel and select 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 keep a lid on it now.
Return to wallpaper thumbnails.