This level has a hidden dispenser which dispenses candy bombs and mystery candies, as all candy bombs and mystery candies can only spawn from above the starting mystery candy.
Actually, mystery candy spawners are not directly implemented in game. The spawn pattern itself spawns candy bombs, and occasionally liquorice swirls or mystery candies. The rest of the tiles where new candies fall from above are really coded as dispensers dispensing no items; this means it may only spawn candies, and it will spawn no other elements. This is true for other levels which feature "hidden" dispensers.