It's to cover up the G-Power inside of the package, so nobody knows how strong the Bakugan is, because kids will just choose the strongest one. In booster packs, it has a sticker on it to cover up the G-Power. In starter packs, one Bakugan has no sticker, one does, and one is closed up into ball form. In battle packs, the two open Bakugan have no sticker, while all the others are closed up. Hope that cleared things up for you.