It's more than just a style
Every leader, I guess, has to work out his or her own approach to social and professional distance, and not all will end up going down the Greg Dyke route.
The late Jim Herbert, for whom I once worked, in a large Birmingham comprehensive, went for something more Czarist. The staff called him "Sir", and he never came into the staffroom without a formal invitation.
The usual reason for asking him in was a presentation to a member of staff who was leaving. He would sit silently with his pipe, looking avuncular, while the proceedings were run with wit and dignity by the chair of the common room association. Me.
Both approaches can work well. Greg's right, for example, to see the value of appearing in the canteen "It sent an important message to everyone; I was both accessible and one of them; that's what I wanted my managers to be."
Jim Herbert, on the other hand, also commanded deep respect. Not for us the head who came down the pub with the lads. Other schools had leaders like that which, to us, explained why we were excellent and they were just very good. Give us Jim, who once sent a teaching practice student packing for wearing a kipper tie.
Reflect for a moment, though, and you see that these two - ex-RAF officer Jim and East End Greg - are not really different. The fact that Greg Dyke goes to the trouble to tell us the canteen story reveals it as a management gesture every much as calculated as Jim's austere approach to staffroom sociability. What both of them clearly had in common was a thought-out awareness of how their actions looked to the people they were leading. Dyke says: "Leadership is often about the stories told about you. You'll be judged more by these stories than by anything you say or write." And we have just proved that very point.