This is Zoro-Urashima meeting in the anime:
-Zoro insults Urashima and ask him to step aside
-Urashima responds to Zoro in a rude way
-Zoro glances at him menacingly
-Urashima is intimidated by Zoro and goes away
Actually this is
canon material. This is something that happens in the manga too, it's was jus offpaneled:
Why did Oda decide to off panel this meeting and yet put this panel suggesting that Zoro has a weird aura only 2/3 chapters later?
This is really suspicious, isn't it?
My take is:
Oda wants to keep the surprise effect for later when the arc is in its crucial stage and at the same time he wants to do some foreshadowing