How does the narrator function in "Vanity Fair"?

The narrator of Thackeray's Vanity Fair is one of the most
interesting examples of the "intrusive narrator" in Victorian fiction. The narrator,
sometimes referred to by literary critics as "the jester" or "the puppet -master"
actually functions almost as a character in the novel, commenting on the main characters
actions and talking about how the characters are being manipulated by the novelistic
process. Among the illustrations Thackeray drew for Vanity Fair were several pictures of
a jester figure that represent the narrative voice. The narrator not only fills in the
backstory and provides exposition, as is typical of third person narators, but also
provides a distancing or ironic effect, guiding the reader to look at the characters
through a comedic lens rather than identifying with their
follies.