It's an old meme that surfaced in the months leading up to the release of Super Smash Bros Brawl. The amount of speculation regarding the roster reached absolutely ridiculous levels. Eventually people would say something like "Character X confirmed for Brawl!" Based on the shape of a shadow or something. Eventually, people started parodying it with things like "Your grandmother CONFIRMED FOR BRAWL" or "George Bush, CONFIRMED FOR BRAWL" etc.