is one piece episode 409 filler?

The episode begins with an explanation of what Amazon Lily is like. It explains that only women live here and that sometimes the women who leave the island bear a child, however only daughters are born.

It also explains that there is a hole at the top of the island with a village in it. The women there are described as hard working and hearty, trained as warriors since childhood, yet graceful.

There is then a shot of a bunch of women looking inside the prison cell Luffy has been brought to. When Luffy wakes up, he remembers what happened and starts asking the women where he is.