backing with the leadline and a horse, you keep your feet still and make the horse move away from you. It shows that the horse respects you and lsitens to you.
This can help get the horses attention on you and do what you ask.
Also if the horse is crowding you and you are talking to someone, you don't have to move your feet to make the horse stop crowding you, but instead wiggle the leadrope so the horse moves away and you can still talk to the person - just as an example.
It shows nothing but a foolish movement on human's part.
And doesn't equal respect either.
I can stand all day long and talk to someone and the horse never crowds me. Horses are perfectly capable of that.
Also not something that translates well at all to show horses, of any discipline. And would get you run off at a training barn too.
Horses should be taught to back by light pressure on nose, tipping nose to chest with light as feather touch, western folks are more prone to work off of chest it seems, but either way, accompanied by a voice command, will work and will get horse used to shifting weight to back end.
The WWJJWHACK method of backing, is a stupid gimmick thought up by fools, who should have it done to them.
Most of the worst problem horses I have come across, are owned by fans of these fools.