It can be made up on the spot (if you bring scissors with) but the angles aren't as good as the ones
in the video (the camera footage wasn't as clear as even phones today are so it didn't catch the
flashes you would make at those angles... also the white bursts in the trick demo were added to
cover all the flashing made while performing the trick).
The explanation is concise, the
gimmick is simple to made, and the trick is flexible (again, keeping in mind that the angles are
extremely weak and should mainly be witness from above).