How does Nevil Shute use imagery in A Town Like Alice?

Imagery:

"An officer came presently, when night had fallen, and inspected the crowd on the verandah in the light of a hurricane lamp; he walked down the verandah thrusting his lamp forward at each group, a couple of soldiers hard on his heels with rifles at the ready and bayonets fixed. Most of the children started crying."

"Darkness was closing down in my London sitting-room, the early darkness of a stormy afternoon. The rain still beat upon the window. The girl sat staring into the fire, immersed in her sad memories. 'They crucified him,' she said quietly. 'They took us all down to Kuantan, and they nailed his hands to a tree, and beat him to death. they kept us there, and made us look on while they did it.'"