I often talk to my creative writing students about the importance of objects in a story. Often at a moment of heightened emotion, when every gesture of a character seems fraught and weighty, the author will retreat from analysis and let the simple details tell the story. It's the way Anse struggles to straighten a wrinkle in the blanket covering his dead wife that tells us so much about their relationship in Faulkner's As I Lay Dying; it's Gatsby's beautiful shirts that he throws around like toys that tell us about his newfound wealth. The fact remains that our lives are cluttered with Stuff, and our interactions with this Stuff often speak volumes about our lives.
Objects take the pressure off of narrative.
If you attempt to analyze the emotions or the state of things at a moment of intensity in your story, the effort will often fall flat. It seems somehow artificial or forced to be told what we're supposed to think and feel about a particular moment in a story. The story begins to feel very fake and heavy if the narrator swoops in to make a grand abstraction of the whole story. That's where objects come in. At a moment of keen emotion, take the weight off by paying attention to concrete details and objects. Let your character fumble with his watch or slice bread. The way he or she interacts with these objects will tell us a great deal more about what's going on than if you simply tell us obnoxiously what's going on.
Objects show what characters value and how they value things.
It's not simply random objects that should be referred to at these crucial moments. Rather, part of your job as a writer of realistic fiction is to create a world and then populate it convincingly, not only with people, but with the very real clutter that fills our lives. If your story is noticeably lacking in all the detritus, from cars to phones to knickknacks our grandparents gave us, the world will feel artificially empty. Part of your responsibility in creating a real world, therefore, is to create a cluttered world, or one that has real interactions with real objects that are consistent with a character's personality. With this crucial element in place, your characters will seem both more normal and more real, and your story will seem both restrained and expressive, telling us a great deal in a subtle way.