Congratulations! It means you have collected 5 or more figurines.
Well, what's happening is that you press the dice button which is beside the play button on the left.
If you go to the selection screen, then you press the dice after picking the figurine that you want to play and press the dice (maybe by accident) instead of the play button, you'll be playing the game in random figurines.
This feature is added so that you try other figurines.