The images show cards with just the suits on them. Is that how the game is usually played?

It seems that playing with a normal deck (suits and ranks) would change the gameplay considerably. For example if you see the A-2-3-4-5-6 of one suit, trade them away, and later see the 7-8-9-T-J, you can be certain it's the 12- card suit. Or more realistically you can do a probabilistic version of the same reasoning by seeing some cards and asking other players questions like "do you have the 8 of diamonds".