The answer is: He pokes at the faults and shortcomings of the pilgrims.
Satire is the use of humor, ridicule and irony to expose someone's ignorance and bad habits. In "The Canterbury Tales," Geoffrey Chaucer makes fun of the pilgrims, who are all very different and belong to distinct social classes. For example, he mocks at the Nun for her large size, at the Knight for being too well-mannered, and at the Friar for accepting presents in exchange for forgiveness.
