The video shows a Single Pole Lifter being tilted with a "sliding weight". The weights are supported by rollers and move freely within a guide supported by the Extended Tilt Assist Lever Arm. As you can see it takes very little effort to move the weights. This Lifter design takes advantage offered by an inclined plane. There are two modes of operation available. One is to provide a weight heavy enough to cause the Carriage to tilt when the weight reaches the end of the incline, or the weight is less than that needed to tilt the Carriage and a final pull provides the additional force needed to tilt the Carriage. In this video the weight is less than the required tilt force needed and therefore requires a final pull nearly equal to the effort required to move the weight along the ramp/guide. The Single Pole Lifter uses the No-Rack design to hold the Carriage fulcrums as the Carriage is tilted.
Single Pole Lifter with Sliding Weights
If you look the pole does have a Rack and Sliding Pinion assembly added, but in this example it is not being used even though it could have been.
The Mechanical Advantage of the Extended Tilt Lever Arm times ( 1 / sin ( Angle of Tilt ) contributes to the total MA of this design.