is one piece episode 669 filler?

As Luffy, Zoro and Viola advance through the castle, they notice that no guards are chasing them. At this moment, a face begins to form from the castle walls, getting bigger until it produces a full body.

Viola curses as this stone monster is Pica of the Spade seat. At the Royal Palace, Luffy's group stands before Pica, an executive officer.

Viola reveals that he has eaten the Ishi Ishi no Mi which allows him to merge himself with any type of rock and he has currently merged himself with the palace which is made entirely of stone. This allows him to control the entire palace.