This is a a great low level plyo to implement prior to a peaking cycle to prep the athlete for the more intensive jumps that will come later.
The object is to rebound off the floor as quickly as possible but still jump as high as possible, try to float in the air. The ground contact time in the video is borderline acceptable. They get better after the first few jumps.
Start with 3 x 15 seconds and build the volume weekly.