Halfway-through: no clubface roll-over, low plane
As the trail arm reaches parallel to the ground on the way through, the trail wrist should be really flexed and the lead wrist in extension, without rolling the wrists over. The club plane comes out low, which promotes a low delivery.
Channel: CraigHansonGolf
Watch official source at 9:32Why this context matters
He calls this the halfway-through position on the way to impact.