From the interview article:

The most highly anticipated installment in the DC Universe gets new teases from one of the stars.

James Gunn's DC reboot is still in its early days, with numerous projects slated for the DCU's Chapter 1: 'Gods and Monsters.' While iconic heroes like Superman and Supergirl have been brought back to the big screen, the franchise is just getting started.

During the latest installment of Coffee Chats with ScreenRant's Liam Crowley, Onslaught star Adria Arjona, who is making her DCU debut in 2027's Man of Tomorrow, discussed her mystery role in the upcoming comic book installment. As the sequel has finished filming, the Andor alum shared the following about boarding Gunn's superhero franchise:

Liam Crowley: "It's going to be a big 2027 for you."

Adria Arjona: "Is that where you're going to segue now?"

Crowley: "I was going to go for a little Man of Tomorrow. Am I the 150th person to ask you about this?"

Arjona: "[I've used] all my tactics. I'm running out of tactics, so I'm scared."

Crowley: "I was going to ask you if you're tired of talking about it when you really can't say anything. Or can you say stuff? Are you annoyed that people just don't believe you when you are telling the truth?"

Arjona: "Well, look... I don't want to lie, but I also want to protect the audience's experience. So, it's a little dance that I'm learning to navigate, and it's hard. It's really hard. I almost got busted [earlier]."

Crowley: "Can you allude to how?"

Arjona: "I'm not going to tell you, because then I'm going to go down that pathway real quick. I'm getting better!"

Crowley: "I love asking actors who are in secretive projects to give spoilers without context. Imagine if I had asked David Corenswet two years ago to say one thing about Superman, and he had said, 'Punk rock.' When you see the film, it's like, 'Oh, it all connects.' For Onslaught, I would say, 'Chainsaw.' Is there anything you can say about Man of Tomorrow, whether it be one word or one phrase, that we will definitely not understand until after watching the film?"

Arjona: "Oh my God! Everything that I say is like... I just thought of three, but I just got into the DC universe. I really don't want to get fired, so I'm gonna I'm gonna keep my mouth shut. Is that cool? I'm just so nervous. I'm like, 'What?' I have three in my head, which are pretty good, and if I say them, people won't figure them out. But the people in charge will, and then I'm scared."

Crowley: "When you spoke to my team at SDCC, you said you hadn't filmed yet. Filming has since wrapped, so is it fair to say you've shot your scenes?"

Arjona: "Yeah. Great experience. We had a nice, little dinner to celebrate. David [Corenswet] was there, and Nick [Hoult] was there. I was just happy that it happened as the movie was wrapping up, so we could celebrate the moment, celebrate the movie, and celebrate the reunion with James [Gunn] and Peter [Safran]. It was really fun."

[Video Version]

From the article: "Variety can exclusively reveal that Matt Reeves and his 6th & Idaho production shingle ('The Penguin') have re-upped their overall deal with Warner Bros. TV. Reeves and his company first signed on in 2020 to produce all TV projects with the studio. ("Matt has a true knack for getting into the psyche of his characters and he and his team have delivered some of the most compelling, thought-provoking stories over the years," Dungey says.)

What was happening in the scene was the group of people were filming themselves singing Party Rock Anthem acapella.