The photograph Diane has chosen is Willsbridge (Over The Edge) by photographer Tom Pope.

SHE WRITES: "I think it's the old couple who make it. Oblivious to the heresy stage-right, they cut a humorous figure, almost as funny as the artist himself. They need an innocent, a guileless child to pipe up and point out, "The Emperor isn't wearing any clothes". Or actually they don't so much need an innocent as to notice the one right next to them, because this is serious funny business. Tom Pope's playing the Fool, a naive but intelligent role. Fools don't play by the rules, in fact they seem incapable of it, and that's what makes them absurd. But that's what makes them visionary too. "Not all there" in this world, they have a special take on it, and were once revered for it.

In Medieval times there was an annual Feast of Fools, when peasants swapped places with their masters under the reign of the Lord of Misrule. This Lord was a kind of anti-Pope - Tom Pope is aptly named.

"...this is serious funny business. Tom Pope's playing the Fool, a naive but intelligent role. Fools don't play by the rules..."

He's disturbing the everyday peace, and it seems only appropriate he's catching himself in the act with photography, an everyday but disturbing medium. Cameras are commonplace but their effects are uncanny, freezing moments beyond the naked eye. Suspended in mid-flight Pope could almost be levitating, magically defying the laws of gravity. He could be a magician, another figure people used to take more seriously. But somehow he cuts a macabre figure. Face white against his dark hair and suit, he could be hanging from the tree, and if he's jumped up into position, he's definitely jumped too high. There's something dark and devilish at work, a Mephistopheles conjured in a sunny, leafy lane.

In Medieval times, of course, the figure of the devil was never far away. He was believed to be constantly on hand to lead us into temptation, and checked only by rigorous social, moral and religious codes - the same codes exposed at the Feast of Fools. Perhaps that's why Pope puts himself in the picture. Unlike most other photographers, he isn't just an observer. He's directly in the frame, just as we all are when it comes to constructing and maintaining everyday codes of behaviour."