How does Jhumpa Lahiri use the minor action and subtle details to express the unmet needs of the characters?

Jhumpa Lahiri does a fantastic job of putting in minor details like the exchange of gum, the details about the use of the camera, the use of the type of clothes that each character is wearing. All these minor details tell a lot about the characters. Usually these minor things are described in a way which makes you feel that the details are being thrown at you but in this short story Lahiri does not do that. For example, Mr. Das is glued to his camera all the time. He never leaves it and seems to care more about the pictures than the holiday itself. It probably shows his need to showcase the happy moments of his life, his need to save those happy moments for later. The gum is an example to conversation. Gum is offered to Mr. Kapasi when Mrs. Das starts taking interest in his story. Gum is also offered to Bobby after he is attacked by the monkeys. These examples show that gum is a minor but significant detail.
In one part of the story Mr. Kapasi is thankful that he was wearing his grey suit and not the other one. This is a minor detail but it shows the growing affection that Mr. Kapasi has for Mrs. Das. Even a detail as small as the color of the suit is shown significant by the author.
Another minor but significant detail is the doll. The author describes the doll as a gorl who's hair has been cut and who is naked. The little girl slams the doll again and again due to frustration. It shows that she is angry at her mother and therefore is taking out her anger on the doll. Lahiri does a very brilliant job of showing the little girl's emotions through her actions towards the doll. She is probably thinking about doing what she did to the doll to her mother. Again Lahiri does a brilliant job of making minor details significant.