All Quiet On the Western Front Initial Reaction

So far I have enjoyed the movie and learning about the numerous techniques directors use to portray the meaning of the film.  The scene where they first come under fire reveals a lot about the characters and how the movie will progress.  We see how each of the men reacts to their new environment.  The directors provide a bit of foreshadowing in this scene and we also get our first view of the madness and chaos of war.  The topic of "dehumanization" is constant throughout the film as the director shows the men referred to using numbers instead of names and corpses referred to as "it" not "who".  Still wondering what the symbolism behind the doors and windows is.  I fell that it is showing how the men are passing from one stage of war to another as the conditions worsen. I'll be watching to see if other scenes continue this trend....