The author uses repetition of the word they're. The author does this to show that they are people to and they all have people that will remember them. The poem is one long sentence to make the reader continue reading, because there is no time to pause or stop.
The first two lines of the poem are about the killed soldiers who are coming home. The authorial intent of this could be to illustrate to the reader what it was like after the soldiers died in the war. It also depicts the travel across the world to make the reader think about how big of a journey going to war is.
The poet uses imagery when he says "their shadows are tracing the curving of the pacific." This has been done because it describes the shadows of the fallen and provides the reader the image of death. It also says "the curve of the pacific" tho show they extent of the travel and commitment of war.
The author uses alliteration when says "telegrams tremble." this is done to emphasise that the people on the home front are trembling in fear.
The poem conveys a mood of somberness and sadness. This is done both to make the reader feel empathetic for the soldiers and sympathetic for their families.