The five 737 fuselages are being backed onto the Boeing spur for delivery to the factory in Renton for the final assembly process. The switchman and conductor are riding here as a safety precaution, watching for problems ahead.
The conductor (standing) is now talking to the railroad's police department about a weirdo standing nearby, taking pictures of this mundane activity. (Just kidding---it was not mundane.)
The foreground flatcar exists only to provide empty space for the tail of the fuselage; that fuselage is mounted on the flatcar in front of this one.
