I'm presuming this has been discussed before, but as I'm new here, thought I'd chime in with a new thread and my take on the topic.
The first time I saw the movie, I was immediately struck by the opening scene in which Ennis gets off the truck with a paper bag in his hand. No suitcase, no duffel bag...just a solitary paper bag containing what he needs to work that summer. Very poignant and humble, reflecting not only his poverty, but the simple life he came from.
But this scene represents one of the several bookends in the movie. When you first see Ennis, he is carrying the paper bag, the wind is blowing, and he is looking somewhat aimlessly around. then flash to the end of the movie at the Twist house. This is the only other time that you see Ennis with a paper bag. Why in the world would Mrs Twist insist on putting the shirts into a paper bag? Ennis folds the top of the bag down in the exact same manner as the opening scene, and as he steps out of the house...you see him carrying the paper bag, wind blowing, and Ennis looking aimlessly around.
Two bookends, with the paper bags......his life began with Jack, his life was over with Jack's demise.