Sometimes the best cue is the one you don't have to give.
The kettlebell can do many things from many different perspectives.
It could be a hip hinge reactive neuromuscular training (RNT). Forcing the hips to push into the kettlebell.
From a biomechanical perspective it could set the CoM posteriorly, altering the hip axis moment arm and making the movement easier.
It could be used to assist with hip extension.
It could be concentric and eccentric hip flexor strengthening.
It could be a neurodynamic mobility exercise that allows for slack in the system with constant knee flexion.
It could force increased internal awareness to the posterior hips.
It could be a novel external input that allows for a self-organizing solution.
It could do many things.
If you're a practicers you should understand the many lenses of this movement. If you're a mover, you should give it a try and see how it feels.