A spectator chooses a playing card and is asked to hide it behind their back.
Now get another volunteer (or use the entire audience) to assist you. Show the wand and explain you will either give them X-Ray vision or that you wand is actually an X-Ray machine. Place the wand in front of the spectator and let gravity unroll the wand revealing the picture and the card.
Now have your other volunteer or entire audience reveal the selection. Your first spectator (the one who picked the card won't know how or why the audience knows the card (show him/her but only if you want to) and the rest of your audience won't know how the accurate card was printed all along!
This is a funny card revalation! Packs small, plays big!