Son extras, esto es lo que he encontrado, aunque creo que los discos extras no vienen en ninguna edición.
And the extra stickers with the guy with green hair is a self portrait of Friedmen himself. The original Dutch/German version of the game came with an extra disk (FanBoy brown if I rememebr right) to put these stickers on, the English version omits this extra disk, but still includes the stickers.