This is called 'skating the floor'. After pouring the concrete, the finishers first wait for it to dry a little... just enough to support their weight. Julie, in the video above, started skating the floor 30 minutes or more before the other finishers. Skating looks like a full body workout... hey... that might be the next exercise craze... I should talk with some people at Nike about it!
Here are some more photos of the finishers doing their work:
