It's shown to everyone, and the magician doesn't touch it anymore. The spectator selects a random card - e.g., Queen of Hearts. The magician holds the DVD and brings the audience's attention to its barcode, more particulary on its number suite. Everybody can constat it's aleatory.
The magician shows his hand empty, and slowly moves it onto the barcode:
Visually, the numbers rearrange themselves to the name of the spectator's card: Q of heart!
The DVD and the magician's hands can be examined immediately.
It's an incredible souvenir for the spectator!
Combination a gimmick and incredible psychological subtleties!