The One World Flag I borrowed from the website that promotes it. The film is set in 2083, and in this film the world has gotten rid of the idea of nations, as they see it as just as a source of conflict. So everything is all one nation, alternativly no nation, but they have a flag.
In the movie you’ll see the female character having this flag on her chest, as she represents the whole earth.
You can also see the rover robot having that flag.
Its an optimistic vision of the world, that we’ve somehow come to a greater step to understand conflicts and know how to reduce them to a degree. There’s no official backstory in the movie as it is now included in the movie, but this flag does symbolize what kind of world she comes from.