The adorable child is cute, to say the least, but they’re also an important character in the movie. The little kid is labeled as Lo’ak, who is one of the children of Jake Sully and Neytiri who we will meet in Avatar 2. The role is being played primarily by actor Britain Dalton, who is much older than this little one, so this scene is likely part of an early sequence in Avatar 2, or perhaps a flashback later, where we see the kids as they’re growing up.
The original Avatar movie is currently available on Disney+. You can use this link to sign up for the streaming service.
Article source: https://www.cinemablend.com/news/2566253/avatar-2-set-photo-reveals-adorable-motion-capture-james-cameron