Closing your city from others, Closing your freedom from the outside as well
Birds is implied to the outside world that you used to see and feel, There's just a shadow that be free to touch the freedom you used to sense.
This poster belong to
Freedom of Movement

In last year's brief we talked about "a world where boundaries are becoming less and less meaningful. Now more than ever, we are one people. No matter where we live, we are all equally powerless in the face of war or environmental disaster."