It is very important that once the right foot lands the left foot lands in a straight line in front of it. This is for a variety of reasons, the most pertinent being the maneuverability of the ball. If the feet are straight it is easy for the flicker to flick the ball in either direction at any height. It is also easier for the flicker to be deceptive.

If the flicker gets his feet in a diagonal line pointing away from the goal then the dragging motion becomes a semi circular one which wastes effort and power. It also complicates matters as far as the position of the hands on the stick as the hands need to re-adjust in order to extend on the follow through and to move round the front foot if it is planted in a diagonal line.
It is very important to make sure that when the back foot lands it is parallel with the top of the circle. This will help ensure that the front foot and back foot land in a straight line.
Notice the rotation that is continuing. Notice all the weight over the front foot and the front foot coming round and almost pointing towards goal.
Notice the back foot beginning to come off the ground so the weight can continue forward. Also notice how the rotation is continuing.