Upon returning to the front from spending time at home, Paul has clearly established that the war has changed him. This is evident in his assertion that "I am not myself here [at home]. There is a distance, a veil between us.” Exploration of this "veil" or "distance" is going to be a goldmine of powerful thoughts. In creating a short story about the thoughts going through Paul's head when he's returning to the front from home, emphasizing how he has changed from "home Paul" to "warfront Paul," is where emphasis should be placed. I think that being able to examine how the conditions of war have changed him would be a good place to focus. Paul has seen horrors in war that are too real if he puts them into words. This is part of the reason that the veil or division between people at home and Paul has emerged.
An interesting short story could emerge if there could be some analysis about how Paul has experienced these moments. The thoughts going through his head would center on the change between home and war worlds, and might focus on how he has fundamentally changed. Clothes that used to fit no longer do. Feelings that he used to experience are different. People that used to elicit one reaction now generate another. In leaving home and going back to the front, Paul has realized that a part of him is dead and will not return. Focusing on this predicament is going to be essential; war has created a "different person."