policeman inside the US base Menwith Hill on July 4th 2003
The symbol of a policeman with a machine gun is saying, "Come inside and we will kill you". It's straightforward scare tactics. Unfortunately the symbol loses its power once one sees the whole thing is just a bluff.
But there are other, subliminal, interpretations. Like: "Look we know you're not into violence, we know you've got no weapons, we know you're all wearing fancy dress and we're protected by miles of fencing and razor wire and cameras. But please understand we are still completely shit scared of you. We need these guns to make us feel safe."
The two guns photographed here appear to be of different types.