Based on the information in the "women were wearing faded house dresses and sweaters ."Line 29 The woman were probably dressed like this because of the story's setting. The story's seems to take place in the 1800s or Mideval times.
The stones are a symbol of death. "The children had stones already, and someone gave little Davy Hutchinson a few pebbles ."Line 320 "A stone hit her on the side of the head." 324 The stones are a symbol something common that is used for an inhumane act of violence. The villagers have thought of this act as completely normal that the kids also take part in.
The lottery may be considered a metaphor. The use of a traditional ritual or ceremony may be a mask for violence. "Tradition as was represented in the black box."(Line 58-59.) In the story there isn't much violence. Everyone seems calm and well-mannered. But towards the end of the story, everyone takes part in the act of aggression.
Uses an ironic tone. From the reader's point of view, a lottery is special grand prize, not a twisted turn of events which involves death. While they were going through the box, "They grinned at one another humorlessly and nervously." The use of irony prepares the readers for the most dramatic reaction.