You can also see lots of videos online of cockatoos playing the shell game, e.g. https://youtube.com/shorts/Pu6O_iOZIO4?si=WEko4pfOekdGIbgF

What I love about these is that you can see that the cockatoo clearly knows that it’s playing a game. It doesn’t tip over the cup to get the reward (or just tip over all the cups, which is the easiest solution if you don’t care about the game). It just indicates which cup is the right one.