The context of the photo is explained at the White House's Flickr photostream:
June 6, 2009
“After his speech in Normandy, a crush of people tried to get close to the President to shake his hand. I noticed this guy waiting patiently and then literally being pushed back into the crowd. I felt bad for him, and mentioned the incident to the President’s trip director, Marvin Nicholson. Marvin pulled the guy out of the crowd, found him a wheel chair, and brought him over to meet the President. He was a French veteran. The man’s face shows his emotion.”
Official White House photo by Pete Souza, via Reddit.
I definitely encountered a number of people like this when I saw the president speak in Eugene. They started sobbing and lying to the people at the front of the line that they'd been there all day, but wandered away and lost their place. Having been there since 4am, I could honestly say they hadn't been, but they were let ahead anyway, where they promptly shoved people out of the way as soon as the doors were open.
I could tolerate the tearful lies, but it was the shoving that angered me.
So happy to see someone who deserves it getting a chance like this.