[Luc]

The contest doesn't make sense to me. I mean, I understand that they are deciding who would give the quickest, smoothest shave. But why would Pirelli do that? His job is to make people's hair grow faster, not shave it off. I don't see the relevance at all. He's promoting his hair-growth product, then all of a sudden they are competing to see who can shave the best.

[kaelidancer]

It's an attempt to expose Pirelli himself as a sham, not specifically a jab at his elixir. His cart proclaims that he is personal barber to the King of Naples, and he certainly makes lofty claims about his barber skills. The people understandably expect someone who claims to be "king of barbers, the barber of kings" to be able to shave a face with some skill.

The point isn't what his product does, it's that he claims to be something that he isn't... that's enough to destroy his credibility.

Barbers in this period were expected to be experts in all manner of sciences... they were dentists, surgeons, and physicians as well as simple haircutters. A shaving contest is the simplest, most basic way of testing a barber's skill... because if he cannot shave a face, it speaks to his competence as a barber on a very basic level.

[Luc]

Ok, that makes sense!
Thanks a lot!