LOL I voted first without realizing what the subject was a about so I voted yes. Figuring flicking with your finger nail or flicking em across the room, things of that nature.
Flicking cards was because some pro started it and a few other players saw it and in a low tone of voice "whoa that is pretty cool" and they started doing it to. Just like the turn your card sideways in the graveyard to indicate you have a card in
exile. Just like writing down life totals on paper, to writing on paper what cards were revealed when they played a
duress. Some players can't/won't stay completely focused on the game. So now the flickering comes along and some are bad. Some are so bad it is like they have adhd and are on crack. Flap, Flap, Flap, Flap, Flap, Flap, Flap, Flap, Flap, Flap, and so on... I think are they are going to blow a gasket soon if they keep that up. Then I like when their opponent has some response like destroying a creature of thiers and they flap, flap, flap, flap for like 2-5 minutes delaying the game to say "It happens".
Everytime I see this I think/imagine Beavis playing going Hehehehe Flap, Heheheheh Flap, Heheheheh Flap, "like um" hehehehe flap, "and ummm" hehehe flap, "I am going to" hehehehe flap.. "It happens"
I do something of the opposite though, I do shuffle my hand and then I will place it face down in front of me. I know exactly what my cards are and focus on what you are doing. I know what my next move is going to be when it comes back to my next turn, I know if I have a response in my hand if the time comes. If I know something is going to happen, I won't delay the game 2-5 minutes acting it is like the hardest decision to say "it happens".