what it also does is makes the audience think you may have done something funny.
when i do my triumph i say how the cards because of density, sort themselves face up and face down. then with a riffle, i do a lil riffle of the cards, they flip over.
now the riffle doesnt do anything, but just because thats what i say and it is a gesture. people think that is what happens.
that is more of a physical move. but a wave is very much like the same thing.
its a gesture that gives the spectator something to take as a reason why somethnig happened. even tho u didnt say it does anything, they take it and will be like. when he waved his hand he did something, or he waved his hands and it magically changed. which is good because it takes the heat off of the move previous to when you waved (the time you actually did something)
do a classic vanish, the audience thinks the coin is in the left hand (I palm with the right) when you wave or blow, the audience thinks that That moment is when the coin dissapeard, not earlyer in the trick.