Looking at someone who looks back at you is, in a sense, the beginning of all society. But, what if what you think is the face of a fellow human being looking back in fact turns out to be just a full-sized photograph on an advertising billboard in the street, or the head of a mannequin in a shop window? More radically, what if the "look" that is thus misguided is actually that of a CCTV camera equipped with facial recognition software or, to give an unexpected twist to our example, the flashing yellow eyes on the wings of a beautifully coloured butterfly?