This scene in the lottery when they annually chose someone to be sacrificed shows Tradition and Sacrifice because in the lottery is said "every summer they did the same thing"this shows tradition
This slide infers that the kids were getting ready to pelt who ever were getting picked and it's foreshadowing that something will happen to gets picked cause in the text it states"selected the smoothest of the rocks" which indicates that something will happen with the rocks
The mood of the slide is gruesome because is shows the person who was chose for the lottery about to get pelted with rocks to death .