How does Owen’s use of imagery in “Dulce Et Decorum Est” help the reader to understand the underlining meaning (or theme) of the poem?

https://www.poetryfoundation.org/poems/46560/dulce-et-decorum-est

How does Owen’s use of imagery in “Dulce Et Decorum Est” help the reader to understand the underlining meaning (or theme) of the poem?   What effect do they have on the reader and our perception of war? In your answer, make sure to identify specific images and explain why the poet created, or included, these images in the way that he did.