I think those are the buses from the "inauguration"... perhaps it was filmed that night. I noticed during the inauguration that had giant lights erected. Why would you need those in the middle of the day? (Incited a mass erection? sorry had to throw that easter egg in) The C-Span version of the inauguration is the key. IT IS SOOOO MUCH DIFFERENT THAN THE "OFFICIAL" STREAMS. So many interesting things can be gleamed. Like the marshals dipping and ducking the cameras, waiting for cues.