As a player, I can disclose my collected tricks during the game
When a card game is still busy (player hands not empty), I can disclose the tricks of my team by clicking a menu item or something.
This is useful e.g. when playing Kingen.
Let's say that the aim of the game is to collect as few hearts as possible. And suppose that I have all hearts and no other cards in my hand. Then we know that all subsequent tricks will be for me.
In that case, it is useful that everyone can disclose their collected tricks, to verify how many hearts everyone has won, and then continue to the next game without having to throw all other cards (and messing up the pile by doing so).