Thanks for sharing this, Dan. I think that your point of image being one thing, and the actual quality of service you receive from the staff of a company quite another, is valid.
And, yes, I would say that, in your first story, Chipper, the "mere" receptionist, had a far greater impact than the company's glitzy ad campaign. He was authentic, service-focused and friendly. Not a bad way for your brand to be perceived.
In the second case, your young and silly bank tellers, I would just say that the very best staff can joke with one customer and interact in an entirely different way with another, depending on how that customer likes to be treated.
Bob and I have had the experience of a restaurant server who doesn't know us being all formal and serious with us. But the moment he or she sees that we value humor and don't take ourselves too seriously, they open up and change the way they interact with us, meeting us on our own terms.
That to me is the key. Being flexible enough to address that person as "Mr. Archer" if they require that kind of respect, and being more playful with people whose personalities are less serious. And I don't see that as being non-authentic, but merely understanding human nature and the wide spectrum of people in this world.
Nice article. You made me think.