Blake from Takeaway section of GtTB: "The hips move towards the target and swivel 45 degrees..."; "...the legs swing the trunk to the right and the undercarriage slides to the left [toward the target] to balance it."
Along with a forward press by the trail knee, the shift of hips toward the target in the takeaway was Blake's answer to keeping the weight balanced between the feet and to keep the head (relatively) still during the backswing. Unspoken is the fact that it precludes hip sway in the backswing.
"The hips move..." and "...the undercarriage slides..."--passive voice again, leaves it unclear as to whether it's an intentional move or a result of other actions. I surmise, however, that it's a result rather than a deliberate motion. Here's how I think it's done. If you start the backswing by moving lead knee toward the ball while keeping the trail knee flexed, in effect, this 'forces' the body to relieve tension by moving the hips toward the target. Do any of you Mindians do this move? SD