Jackson's use of language creates a hint of uncertainty for the reader. While the overall mood is positive and laid-back, you can't help but feel a tiny bit of unease as you're introduced to a world in which "the lottery" could mean anything.
The uneasiness is an underlying mood created not by the words that are present but by Jackson's omission. Jackson neglects to tell us what the lottery is right off the bat, leading us immediately into the next paragraph with the questions: What is this event? And why do so many villages do it?
Let's not overlook the final half of last sentence in this first paragraph, either:
... in this village, where there were only about three hundred people, the whole lottery took less than two hours, so it could begin at ten o'clock in the morning and still be through in time to allow the villagers to get home for noon dinner.
The villagers can get home in time for "noon dinner," yes, and our initial reaction is to assume all the villagers can go home for the meal;...
(The entire section contains 3 answers and 590 words.)