How does Sembene Ousmane use imagery in God's Bits of Wood?

Imagery:

"Striking brutally through the cloud curtain, like the beam from some celestial projector, a single ray of light lashed at the Koulouba, the governor's."

"The faces seemed to have lost all trace of personality. As if some giant eraser had rubbed out their individual traits they had taken on a common mask, the anonymous mask of a crowd."