The old mime is practicing mobile striking with attention to defensive strokes. You will not see a lot of blocksthere being only two, roof and umbrellabut note that most of the strokes that look like hits, would go against the opponent's weapon or weapon hand and are classed as defensive strokes. A beat is a defensive stroke that hits a weapon and not the hand.
Thanks to Lynn for posting all of these videos in such a timely fashion.
link jameslafond.blogspot.com
James LaFond demonstrates the shadow stick mobility exercise: