Wonder Woman Trailer Breakdown: 23 Things You Need To See
21. The Amazonian Senate?
We're likely to see Wonder Woman in man's world for most of the film, but the opening at least will be set in her home land of Themyscira. There, by the look of this shot, we'll get to see some of how the Amazons rule.
This seems to be a sort of council room, with important artefacts in the background - most likely the film's version of the Magic Sphere that allows the Amazonians to look in on the events in the world of man.
The senate-like set-up would appear to be where major decisions are made, so it wouldn't be at all surprising if this is where the decision to intervene in the war is made. Either that or it's when Hippolyta allows her daughter to leave to look into the war.