The picture shows the young boys collecting stones for the lottery. These stones symbolize death because they are used to murder the "chosen one".
"The black box grew shabbier each year; by now it was no longer completely black but splintered badly along one side." (Pg. 27) This example of imagery describes how damaged the deathly box looks like.
There are several allusions found in the names of the characters in the story. Mr. Summers presides over the ceremony with a sunny disposition. Mr. Graves assists in the deathly ritual. His name refers to a graveyard. This image incorporates a gravyard (Mr. Graves) on the bright and sunny day of the lottery (Mr. Summers).
"It isn't fair!"
The tone is neutral throughout the whole story. On page 27, the narrator explains the process of the lottery and describes the change from wooden chips to small pieces of folded paper. The citizens are required (even brainwashed) to adjust to the new system.
The three-legged stool symbolizes society falling apart. It carries death after Mrs. Hutchinson sat on it and the black wooden box stood on top of it.
One theme developed in "The Lottery" is the idea that just because something is a tradition, participating in it doesn't always make it right. The picture shows everyone in the town gathered to watch and perform the murder of Mrs. Hutchinson.