It's a scene from the anime/manga between Luffy and Vivi. So Vivi is the princess of Alabasta and she is trying to stop the war between the Kingdom and the Rebels by appealing to the Rebels, who is led by her childhood friend Koza. But in the middle of the journey to the rebels, Luffy stopped and disagreed with her, saying that she's naive for shouldering the burden alone/ thinking she can stop the war alone while also wishing no one dies in the war, hence the fighting. Eventually they agree that Luffy will go to fight Crocodile (the villain who is responsible for the conflict- lack of water- that made the Kingdom and the Rebels fight each other) and that they will risk all their lives to beat Crocodile and save Alabasta.
It was honestly a pretty good scene in the ice show

the camera couldn't get too close but it's not just the facial acting, the physical acting was also really good. And they did a couple skating elements together like paired butterflies to convey the argument and the fight. There have been a lot of comments for smiling Shoma as Luffy, but I thought his acting here was really well done, balancing this sort of straightfaced brutal honesty when he points out that the plan isn't working and gradual frustration when he had to face the increasingly distressed Vivi.
And on the fight: they were shadowpunching each other (although Shoma and Marin did say they hit each other accidentally in practices, lol) but Shoma was really good at phsyically conveying the reactions of being punched. Fans said that he even did a trick to make sure that his straw hat flew away right on time when Marin punched him, which I thought seems like a small detail but it's probably harder than it looks to arrange.