This is a good drill for those who have hips that rotate too fast. It promotes more lateral weight transfer from right to left foot and keeps your lower half more connect to the top.
I’ve been doing this exercise a bit at night and it’s helped me with the consistency of my downswing and ball contact.
According to Fowler, “The idea is to feel pressure subtly shift from my right glute on the backswing to my left glute at impact. But neither glute should ever lose contact with the wall. If you have an air disc or small throw pillow handy, prop it behind you to get better feedback.”
This drill feels a bit strange. Give it a shot though and let me know how it works for you!