is one piece episode 91 filler?

As they sail away from Drum Island, the Straw Hats gaze with wonder at the sakura effect over the island. Usopp wonders why Chopper looks so distant, sitting on a railing as if lost in thought.

The others are not worrying about that. Sanji says his first trip as a "man" is a rite of passage.

His thoughts are on Hiriluk and Kureha. It does not take long before the horseplay begins, with Luffy entertaining the others with his "nose chopsticks" trick.