How does the author use figurative language to establish a tone of wonder in the first two paragraphs of the essay

Most of the figurative language in Liam O'Flaherty's story "The Sniper" occurs in the first paragraph.  

"Dublin lay enveloped in darkness. . ."

Here the figurative language makes the reader imagine the darkness like a blanket being wrapped over something.  Or perhaps it makes the reader think of the darkness encasing the city like an envelope encases a letter.  Later in that same sentence, the author describes "fleecy clouds."  The image that is brought to bear is light and fluffy, which is similar to the fleece coat of a lamb.  

The best use of figurative language in the first paragraph occurs in the final two sentences of it.  

. . .  the heavy guns roared. Here and there through the city, machine guns and rifles broke the silence of the night, spasmodically, like dogs barking on lone farms. Republicans and Free Staters were waging civil war.

Guns roar like lions.  Gun shots are like barking dogs.  The entire opening paragraph expresses a grim tone.  This is not a happy picture being painted.  It's dark, it's lonely, it's heavy, and it's violent-sounding.  That tone is carried throughout the story to its utterly depressing ending.