How does George Orwell use imagery in The Road to Wigan Pier?

Imagery:

The shop was a narrow, cold sort of room. On the outside of the window a few white letters, relics of ancient chocolate advertisements, were scattered like stars. Inside there was a slab upon which lay the great white folds of tripe, and the grey flocculent stuff known as 'black tripe', and the ghostly translucent feet of pigs, ready boiled. It was the ordinary 'tripe and pea' shop, and not much else was stocked except bread, cigarettes, and tinned stuff.

There is the heat—it varies, but in some mines it is suffocating—and the coal dust that stuffs up your throat and nostrils and collects along your eyelids, and the unending rattle of the conveyor belt, which in that confined space is rather like the rattle of a machine gun.