A small white envelope is placed off to the side of the table. A deck of cards is introduced, fanned and shown to contain a random selection of playing cards. The deck is then cut in half by an audience member. The cut portion is divided into three piles across the table and three cards are pushed out of the three different piles. The mentalist asks the audience member if they would venture a guess as to which cards they chose. The participant makes a few guesses and gets close but ultimately misses the cards. The cards are turned over shown to be (for example) the five of clubs, ten of diamonds and jack of spades.
The audience member is then instructed to pick up the envelope. Crack the seal and remove what's inside. They find three miniature playing cards. All three are exact matches of the cards chosen just moments before.
... this has nothing to do with elephants