Sometimes, it’s best to let the photographer explain. This wonderful photograph was taken by Flickr user
An Untrained Eye who has a small but excellent photostream over there.
"This is one of those photographs that occasionally repay the futile efforts we street photographers so often make in search of the arresting image. When I saw the stencilled girl (who is actually much smaller than she looks) on this street corner, I was convinced I could catch a great picture of her looking back over her shoulder at someone heading up the street. So I crouched down in the Lisbon drizzle and waited. I must have been there for twenty minutes and taken a dozen or more not entirely satisfactory shots - the person needed to be walking up the near side of the street; there couldn't be any other people in view; and so on - when this chap obligingly looked round at, well, the decisive moment."
