That's an interesting point, but I would suggest that cards in and of themselves are boring, and its up to the performer to make them interesting. Therefore I believe the focus should be the interaction between the performer and the cards. Otherwise it would seem to follow that the focus of a football game is the ball, or, to extend the logic, the focus of a TV show to be the TV. To my mind, in each case, the cards, ball or TV are merely the medium by which the "show", whatever it happens to be, is conveyed.