The fortune teller mini-game is a luck based mechanic where you can win rare items. Reveal cards to unlock different rewards. If you find the lucky card you'll get the reward from every card.
Come back every day to reveal new cards!
Once you unlocked the fortune teller zone, you can access the mini-game by tapping the "Cards" icon in the right corner of the screen:
Choose the card you want to play, the first one is always free:
Hit the jackpot and you'll all the rewards: