The goal is to trick your mind into thinking that you haven't just jumped off a ledge, if only for a very brief, lucid moment.
Here's is an example of an elevator style jump:
By hopping off the platform backwards (facing the platform), you're accomplishing a few things unique to this style of jump. The small hop tricks your mind into believing you're still standing on the same ground you started on... we didn't hop very far, so it's unlikely anything is wrong. Meanwhile, facing the platform further helps sell the illusion to your mind by providing static backdrop... my environment hasn't changed, so I must be okay.
For a very brief moment, your mind is put at ease... everything is cool, nothing is horribly wrong. And then you free fall and have a chance to panic.
If you had instead made a big leap off the platform or let yourself tip over, your instinctive reaction is to prepare for landing, and brace for impact (something that doesn't quite come with bungee jumping, and is a thrill in and of itself).
