[Yoda]

That 'thing' is the line of compression - the force you are putting 'through' the ball, the nail you drive through the inside back corner.

I really like EdZ's Driving the Nail image. It encapsulates the concept of Timing (6-F) and is very useful in getting it right. Similarly, this is one of the reasons why training with an Impact Bag is so effective.

Where to 'drive the nail' is strictly a product of the selected Delivery Line. When Tracing the Geometric Plane Line, the target is the middle of the back of the Ball. When using either of the Visual Equivalents of that Line -- Arc of Approach (Curved Clubhead Blur) or Angle of Approach -- the target is the inside-aft quadrant (2-J-3).

No matter which Delivery Line is monitored -- the Geometric or the Visual -- the Clubhead's actual Arc through the Ball is identical: through the inside-aft quadrant.