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Barack Obama joins Open Government Partnership for group photo

Allan Tannenbaum-Pool / Getty Images

U.S. President Barack Obama waves while standing with other leaders during the Open Government Partnership event at the United Nations September 20 in New York City. The United Nations General Assembly kicks off September 21, with leaders from around the world attending.

I don't know much about diplomatic protocols, but I would guess that waving during the group photo is something to avoid.

President Obama's hand accidentally blocked the face of the President of Mongolia, when Obama waved while a photo was being taken at the United Nations. NBC's Brian Williams reports.