What are some literary devices in "The Lottery"?

Shirley Jackson uses imagery and irony throughout her short story "The Lottery."

The story opens with a strong imagery as the narrator describes the setting:

The morning of June 27th was clear and sunny, with the fresh warmth of a full-summer day; the flowers were blossoming profusely and the grass was richly green.

By the end of the story, however, it's clear that Jackson intends for the quaint imagery to be read as ironic in contrast...

Shirley Jackson uses imagery and irony throughout her short story "The Lottery."

The story opens with a strong imagery as the narrator describes the setting:

The morning of June 27th was clear and sunny, with the fresh warmth of a full-summer day; the flowers were blossoming profusely and the grass was richly green.

By the end of the story, however, it's clear that Jackson intends for the quaint imagery to be read as ironic in contrast with the horror of the brutal murder of Mrs. Hutchinson, which tainted that beautiful day with blood. 

In another instance, Jackson portrays this day as some sort of summer holiday. In retrospect, the children gathering up stones should seem disturbing, but Jackson's inclusion of the girls standing "aside, talking over their shoulders at the boys, and the very small children" who "rolled in the dust or clung to the hands of their older brother and sisters" provide an innocence to this scene. Again, the bloody ending makes this imagery ironic. 

Jackson includes this quaint and seemingly innocent setting in order to demonstrate that anyone at any time can commit awful acts of evil if their society demands it. This theme was particularly relevant when this story was written, just a few years after the end of World War II.