There is some figurative language here: simile, personification, and lots of imagery.
Figurative language's purpose has always been to describe vividly to the reader what the author is trying to picture. This sentence should do the exact same.
Answer: The purpose of this sentence is to vividly describe to the reader what the author is seeing.
Sorry, if there's an even deeper meaning, I don't know. I'm only in middle school.