As for winnings, the amount of tokens you get depends on the type of hand you had and the bet you made before the game started. Otherwise, you will lose those cards when they are replaced.
When you do get a winning combination, make sure you remember to keep all the winning cards before selecting 'Deal'. In the case of the Royal Jelly Flush, my guess is that it's a Royal Flush consisting of an all-slime suit. The winning combinations are shown at the top of the screen and follows the same rules as a real-life poker game. The game is lost if you don't get a winning hand after requesting a change of cards. Before starting a game of poker, you will be allowed to change the amount of tokens you want to bet for each set of card dealt, and you will also have one chance to switch out any card or even all the cards you don't like.
