I think it's largely a class thing. The writer thinks that the restaurant owner is lesser than her, so his attempts to be friendly and engender good will are manipulative and, god, i don't even know the right language. Like he should be acting subservient instead of friendly, and treat them in accordance with their station or something? Providing a discount is an insult because it implies she couldn't pay full price? Or it's just good old fashioned racism. I know a lot of people scoff at the idea of racism being directed at non-Anglo white people but it's still a thing. It's not as destructive as racism directed at non-white groups, but there are still plenty of East Coast WASPs who think anyone who can't trace their ancestry back to the battle of Hastings is less human.