When Wan was promoting Aquaman in China late last year, Warner Bros. asked him to guess what the most popular scene was for that country.

"I'm thinking of all the crazy set pieces and all the cool visuals and all that," Wan tells The Hollywood Reporter. "I wasn't even remotely close. They said, 'It's the scene where Amber [Heard] eats the flower."

The scene in question finds Arthur/Aquaman (Jason Momoa) and Mera (Heard) in Italy, searching for Atlan's trident. Mera is unsure how to act among the surface dwellers, and in a market she ends up eating a flower as though it were a piece of fruit. Not one to make her feel out of place, Arthur follows suit and eats a flower as well.

"When he is in her world, he's the fish out of water. When she's in his world, she's the fish out of water. And it is about finding those moments," says Wan, who notes he spends as much time working on the small human moments as he does on the set pieces.

While Mera and Aquaman are among comics' most enduring couples, Wan wanted their relationship to build slowly over the film, leading up to Mera giving Arthur a kiss before he goes off to fight his brother, Orm (Patrick Wilson).

"She thinks he's a buffoon to begin with, and then she slowly warms up to him," says Wan. "I didn't want to start with them already there and even then, maybe after they kiss they still kind of bicker. It's part of that fun, like [Spencer] Tracy and [Katharine] Hepburn."

Aquaman is on track to earn $900 million globally by the end of its run and has already earned $261 million in China. For more from Wan, read our full conversation with him.