I'm guessing the joke is about how that specific card requires the player to offer a handshake with the opposing player receiving a minor penalty if they refuse?

OmniGManJr said:

I'm guessing the joke is about how that specific card requires the player to offer a handshake with the opposing player receiving a minor penalty if they refuse?

I believe shes also showing "Unity" in hand, which makes the handshake mandatory and cannot be refused. I think shes trying for forced unprotected handholding.