How is Ford Madox Brown's nineteenth century painting titled "The Pretty Baa Lambs" slightly humorous against the other images on pages 66 and 67?

Ford Madox Brown's painting portrays the Virgin Mary and Child as shepherding sheep, and it is not the classic representation of either character. The painting is humorous as it is paired with more formal portrayals of the Holy Mother and Child on the same page. The contrast between the formal icon Virgin Mary present on the page and the human Mary presented by Brown's painting creates an obvious clash against traditional religious beliefs.