I thought this an interesting picture. It reminds me of the scene in the 1956 version of the film '1984' in which Winston Smith is stopped by a police vehicle and questioned whilst walking along at night.
The poster itself is quite sinister, though it has a nice poetic touch.
I imagine that this photo could be used as the starting point for some creative writing, or a discussion about the pros and cons of CCTV in public areas.
Interestingly, the position of the poster -- high up on a lamp post, unlit, and facing the wrong way in a one way street -- is such that the only people likely to see it are those sitting in the back row of the upper storey of a double-decker bus looking backwards.
In other words, whilst the poster may well be sinister, it is also pretty pointless.