All the action, if you can call it that, takes place in front of the little house. There is little actual action. The rest is reported and we are looking at reactions. It is not just the remote past that is talked about. Characters come in and report on what has just happened to them.
Key events take place off stage.
This kind of theatre is understandable when a character must report on huge battle scenes with casts of thousands. Obviously the choice was made to narrate, but it wouldn't have been too hard to show action. It would have involved more actors, and heaven knows you don't want to have too many actors in a production if you want to see it produced. Still, add another three or four small parts, and the action of the play would have been action. Finally, a violent scene is related, part of which might have been shown instead of told.