Was it an inside joke?

When they were driving down (or up) the Lincoln Tunnel, Jay was flipped upside down while Kay played a song by Elvis. There is a very brief shot of Jay's feet tapping away. It seemed like it was a joke where Jay is dancing to the music in Elvis style... Does anyone else see it or is it just my imagination? The shot seemed liked it was put there for a purpose, was it a Elvis reference?

It reminded me of a scene from Forrest Gump where Gump is dancing like that.