I assume it's his.

It is still drizzling steadily. Impressively, this is not deterring a yellow digger, two orange diggers and two piledrivers at the Building Site End at which there is a great deal of crashing, grinding and banging going on.

More sedately, at the City End, a man in a floppy white hat has just poured himself a cup of tea from his flask and is sitting out there beneath his umbrella watching the rain hit the grass.

At least, I assume it's his umbrella.