If the grip is supported on the tillering tree so it cannot tip, and limb strength is balanced so the hook, placed at the string hand fulcrum position, comes straight down without wandering off toward a stronger limb, that's pretty good limb balance, and the bow will pull nice and even into the relaxed bow hand so there's little challenge to a consistent, repeatable grip.
If instead someone wanted to know exactly where the pivot point was, or wanted to apply more pressure low or high, they could place something under the grip that allows it to pivot. Then that pivot could be moved left or right until the bow balanced when drawn, or placed where wanted, then limb strength adjusted as needed to achieve balance.
I cut the end off of a big double cut halfround file for this.