The author uses these words to create a sad and melancholy mood.
The mood is only identified by reading the text. In this case, the reader must pay attention to specific words, which determine feelings that must be felt through the words read.
An example of this can be seen in the excerpt above through the words "darker aspect," "beetle-browed," "gloomy," and "ponderous."
More information about what mood is at the link:
https://brainly.com/question/14406936