The best response to the question regarding how the author’s use of imagery conveys information about the historical setting in "The Slow March of Light" is:
The imagery implies that people in East Berlin did not get enough to eat.
This interpretation aligns with the details provided in the passage, specifically the reference to the man's haunted eyes and the elderly woman's threadbare shawl, which suggest deprivation and hardship typical of the historical context in East Berlin during that time.