Relative to a traditional swing, there will be less speed in the system, but a higher percentage of that speed will be transferred to the club at impact. Cathy is demonstrating this with her relatively closed hip and shoulder lines here.
Lead-arm-only golfers must be careful to have the center of the club's mass stay beneath the grip early in the downswing. This will help them use physics to their advantage and square the face in time for impact.
