This is a poster from a Soccer/Football tournament of some kind, called the FA Cup. Clearly, Sega had some sort of a sponsorship role with this, and then produced a poster. However, whoever made it didn't do a very good job. Sonic has blue arms, and they forgot to color his shoe stripes too. He's been modified to be shown holding the trophy to the event, while fans cheer in the background. They have also changed the art so his foot is on the soccer football. It's too bad they missed so many details, the FA Cup is a popular event.