On his trip to get a burger with Brian Williams at Five Guys this afternoon, the President appears to have learned of the existence of a Defense Department intelligence arm, the National Geospatial Intelligence Agency, from an agency employee also at the burger restaurant. "So explain to me exactly what this National Geospatial..." Obama said, after the worker mentioned his employer, according to a video of the event. "We work with, uh, satellite imagery," the worker, Walter replied. A POLITICO reader caught the exchange, which starts around 5:45 on this C-SPAN video. The transcript: Obama: What do you do Walter?...