There is a residual energy in an empty room, after a party. There is a presence of people, even though there's no one there. There is calm, in those empty rooms, even though there was chaos before. Beer glasses, cigarette bites, napkins, papers, tickets... they are all remains of people, indicating that something happened there. An empty stage may be an omen for something to come, it brings expectation. But an empty stage surrounded with garbage does not make us look forward or yearn for something to come: either we realize that we are too late or we can dream of what was. An empty stage brings us an idea of past, of something that happened. It's like a memory, where we try to rebuild all those things that were left behind.
Cartier-Bresson said “photographers deal in things which are continually vanishing, there is no contrivance on earth which can make them come back again. We cannot develop and print a memory". An empty stage surrounded with garbage gives us just that: a thing that was and will not come back; a memory of a place, of an event.