I feel that the stories interior is based on the grandmother who has transformed herself from being a person that is self centered and who manipulates other people to having sympathy and a warm corner for other people including the killer.It also tells us no matter how many bad deeds you do in life but as long as you repent to God with the intention to be a better person and not repeat those mistakes can actually bring you close to God. The interior of the story also tells us how a person thinks that everything they do is right no matter how big the crime, instead of realizing what actually is the right thing, which causes a conflict between our moral and ethical beliefs and our actions caused by those beliefs