Keep the club on the lead side of the body
For his right-handed single-plane motion, the instructor describes the club-to-body relationship as lead-sided: the back end of the club stays on the left side and leads through the strike. He says maintaining that relationship lets the swing return to plane and trains lead-sidedness, swing length, and swing plane.
Channel: Todd Graves
Watch official source at 9:25Why this context matters
The directional wording is for a right-handed golfer.