hes probably not testing big structural design stuff, like: will the wheel fit? That would have been done during developing of the a/c. My guess is he's testing the Communication interface for the ground crew.
This is in fact vibration testing. The nose strut will be tested through all degrees of extension for vibration while hydraulics are applied by use of the test stand you see in the background. The unit that is attached to the nose wheel assy hub will simulate this vibration by use of a DC motor exerting simulated loads. The wires are part of the vibration analysis equipment designed to measure the IPS or (inches per second). IPS are also also for the standard of measure on engine vibration equipment.