How do imagery and sensory words enhance a reader's understanding of a poem?

War

by Ellen Glasgow

Ripples of ribbons borne on high,  

Bloodstains upon a brazen sky;  

From cannon belching on the plain,  

Fire that by fire is fought again.  

A flash where steel by steel is met;  

A fume of smoke and blood and sweat.  

Sharp from the smeared and trodden gorse

The death-cry of a wounded horse.  

Dust of a plain ground into red  

By armies of majestic dead.  

Gaunt shadows on the changeless sky,  

A flock of vultures swarming nigh.  

Mid ashes where a hearth has stood,  

Children that cry aloud for food.  

Where green the peaceful highways run,  

A woman ravished in the sun.  

And far across the reeking sod  

A Nation sounding thanks to God.

Explanation:

because he was killed by the black arrow.