As you see in the demo, this is a cute, commercial effect. What you don't see in the demo, but might
be important for experienced napkin rose makers, is that the rose needs to be set-up before you
present it to your spectator(s). Since one of the charms of the napkin rose is making it in front of
your audience, potential buyers should realize that the routine does not accommodate this aspect.
Personally, I will want to come up with a way of ringing in the gimmick after the rose has been made
in full view, and I was a bit disappointed to find that this was not discussed.