I was referring to the fact that IGG, the card, and I GG, the pun, are both answers to the question as posed; the card is the only method of performing the action described. As opposed to Harem/Cellar, where there is only wordplay and no relation to the game.
Someone find me a better word than entendre here, please; I guess I could just say it works on two levels, as opposed to the other puns which are just plain ol' puns.