From Lucie & Simon's webpage on the piece:
The silence of the world, like a quotation, is suddenly endowed with an oppressive eloquence. Small intrusions are the true sparks here, because their disconcerting presence disrupts the majestic calm of the streets and squares. Are the latter guilty or victims? The fate that governs these shots in a tangible way is not the result of decisions taken by metaphysical powers, but stems uniquely from the imagination of the two creators of these photos, Lucie & Simon.