How does the author use physical description and dialogue to create a vivid portrayal of Chinaboy's character on the first page of the short story below?

The sun hung well towards the west now so that the thin clouds above the ragged horizon were rimmed with bright yellow like the spilt yolk of an egg. Chinaboy stood up from having blown the fire under the round tin and said, 'She ought to boil now. The tin stood precariously balanced on two half-bricks and a smooth stone. We had built the fire carefully in order to brew some coffee and now watched the water in the tin with the interest of women at a childbirth.

'There she is,' Chinaboy said as the surface broke into bubbles. He waited for the water to boil up and then drew a small crushed packet from the side pocket of his shredded windbreaker, untwisted its mouth and carefully tapped raw coffee into the tin.

He was a short man with grey-flecked kinky hair, and a wide, quiet, heavy face that had a look of patience about it, as if he had grown accustomed to doing things slowly and carefully and correctly. But his eyes were dark orien- tal ovals, restless as a pair of cockroaches. 'We'll let her draw a while,' he advised. He put the packet away and produced an old rag from another pocket, wrapped it around a hand and gingerly lifted the tin from the fire, placing it carefully in the sand near the bricks.

We had just finished a job for the railways and were camped out a few yards from the embankment and some distance from the ruins of a one-time siding. The corrugated iron of the office still stood, gaping in places and covered with rust and cobwebs. Passers had fouled the roofless interior and the platform was crumbled in places and overgrown with weeds. The cement curbing still stood, but cracked and covered with the disintegration like a welcome notice to a ghost town. Chinaboy got out the scoured condensed-milk tins we used for cups and set them up. I sat on an old sleeper and waited for the ceremony of pouring the coffee to commence.

It didn't start right then because Chinaboy was crouching with his rag- wrapped hand poised over the can, about to pick it up, but he wasn't making a move. Just sitting like that and watching something beyond us.

The Port Jackson bush and wattle crackled and rustled behind me and the long shadow of a man fell across the small clearing. I looked back and up. He had