Final answer:
The personification reflects the postmaster's deep yearning for friendship and companionship, which he projects onto nature.
Step-by-step explanation:
The personification in the given sentence conveys that the postmaster has a deep longing for connection or companionship. By attributing human emotions to the bird and the leaves, the author highlights the postmaster's intense feeling of yearning for friendship, so much so that he sees this longing reflected in nature. This longing seems to be a pervasive force in his life, coloring his interactions with the world around him and amplifying his sense of isolation or desire for kinship.