In Chapter 2, an allusion to the "pert dunces" of Molière helps paint a picture of the type of person Passepartout is:
Passepartout was by no means one of those pert dunces depicted by Molière, with a bold gaze and a nose held high in the air; he was an honest fellow, with a pleasant face, lips a trifle protruding, soft-mannered and serviceable, with a good round head, such as one likes to see on the shoulders of a friend.
Molière was a 17th-century French actor and playwright known especially for his farces. Plays such as Tartuffe and L'Ecole des Femmes have been majorly influential on French comedy to this day. Many of his characters were people whose good looks (or "pertness") concealed some kind of character flaw, such as poor intelligence or hypocrisy. By contrasting Passepartout with Molière's "pert dunces," the narration make the point that Passepartout is exactly what he seems: a decent guy. At the same time, the reference to Molière, a paragon of comedy and satire, suggests that the reader should look out for humor and biting satire in Verne's novel. This is not the only clue that the novel is comedic and satirical. The lighthearted tone has already established that Fogg is a character who deserves to be laughed at. He actually might be something like a "pert dunce." Passepartout, on the other hand, is a stand-up guy. Jokes may come at his expense, but the novel generally does not mean to criticize him too much.
It is important to note the casual influence of phrenology on this characterization of Passepartout as an "honest fellow, with a pleasant face." Phrenology was a pseudoscience that was popular during the 19th century and that played a major role in imperialism. It held that someone's character could be deduced from their looks. This idea led to the creation and widespread dissemination of many stereotyped images (for example, the idea that a physical disability signals evil). Although phrenology has long since been debunked, its traces can still be seen in stereotypes about race, ethnicity, class, and disability.