The site you linked it from might have cross site linking turned off. Best save it and upload it to a place like Photobucket.
If you can get me the img src URL, I can do it for ya.
http://bp2.blogger.com/_L6pDyjqqsvY/SIpJaNO6tPI/AAAAAAAAPTY/CiHmXt7eoos/s1600/obama%2Bthanks%2Btroops.png