Is he a true lefty, or just shooting left handed (left eye dominant)?
That's what I was thinking. Or some people just wear their watch on the dominant hand anyway, because they find the watch hangs up on stuff like car doors, or whatever all day long otherwise. It's not significant to me.
Someone's already claimed that by going through the EXIF data, and error level analysis that the image the White House released was shopped.
However, that could just mean color balance, contrast, white levels etc. and nothing material to the "reality" of the image itself.