Guido has previously noted that balding Boris is losing his locks, so it is no surprise to see his hair cropped shorter and brushed forward to disguise that thinning top:

It is more flattering from above:

The age old rule in British politics is that bald men in the television age do not beat rivals with a full head of hair. Think Tony Blair versus William Hague, IDS and Michael Howard, nor can we forget Maggie versus Kinnock. In every election the slap-head loses. Could Boris’ new baldness-battling barnet be a sign that his leadership campaign is shifting up a gear?

UPDATE: A friend of Boris gets in touch:

“Don’t get too excited. Cropping shorter isn’t new Mayoral policy, it’s something he revisits every few months with the help of his Turkish barber!”