Much like the Guitarface, the Pokerface is used to hide emotion during
poker or any other game involving cards.
Most
people are incapable of this
action as they tend to snicker or jump up and down screaming "FUCK YEA I'M SO GOING TO KICK YOUR ASS WITH THIS 'GET OUT OF JAIL FREE CARD' WHEN IT'S MY TURN AGAIN YOU FUCKING PUSSY!"