To illustrate the author’s calm, contemplative mood
This is the best description for the excerpt. The author illustrates his mood with words that identify his mood at the moment when he wrote it. He has written about his thoughts as well and his view of nature.
Allusion is the type of figurative language used here, I believe.
1) Did she have the courage to leave a cushion job
2) Finally she worked up the courage and turned on the computer.
3) His words put courage into every heart
4) The child was small and somewhat deformed, but of great courage and intelligence.
5)Finally she dragged up the courage to broach the subject.