The official photo was released on the official White House Flickr stream. Here is the description.
Now the way I read that it doesn't really forbid Photoshopping. But I don't think they could since it is an official government photo and according to Wikipedia:
Even on whitehouse.gov it says "Pursuant to federal law, government-produced materials appearing on this site are not copyright protected."
President Barack Obama shoots clay targets on the range at Camp David, Md., Saturday, Aug. 4, 2012. (Official White House Photo by Pete Souza)
This official White House photograph is being made available only for publication by news organizations and/or for personal use printing by the subject(s) of the photograph. The photograph may not be manipulated in any way and may not be used in commercial or political materials, advertisements, emails, products, promotions that in any way suggests approval or endorsement of the President, the First Family, or the White House.
Now the way I read that it doesn't really forbid Photoshopping. But I don't think they could since it is an official government photo and according to Wikipedia:
A work of the United States government, as defined by United States copyright law, is "a work prepared by an officer or employee of the U.S. government as part of that person's official duties."[1] The term only applies to the work of the federal government, including the governments of "non-organized territorial areas" under the jurisdiction of the U.S Government,[2] but not state or local governments. In general, under section 105 of the Copyright Act,[3] such works are not entitled to domestic copyright protection under U.S. law, sometimes referred to as "noncopyright."
Even on whitehouse.gov it says "Pursuant to federal law, government-produced materials appearing on this site are not copyright protected."