Broader meaning...?

Could it be that a broader idea to the story is the writer/director providing some sort of theory as to why London, or megacities in general, are increasingly seen as impersonal, soulless places? ie. those who inhabit these cities are becoming more unfriendly and soulless (the doppelgangers), this perhaps linked somehow with the idea that in parallel, people are becoming increasingly more vain (the idea of the mirror image getting revenge).

It seems to me that beyond replacing their originals, the doppelgangers aren't actually evil. They don't seem intent on killing off loads of other people or going on crime sprees or anything like that, they're just substituting themselves for the originals and gradually making the city a duller, less friendly place.

This ties in with the idea that people beyond the circle of the family in the film have also been taken over by their doubles (the old lady with the sixth sense pointing them out in the train, the dogs, Asian man with oranges, stats about the increasing number of mirrored people in the x-rays, etc).

I think the film could be an analogy for the way the writer sees society heading.