Well, it's an amusing sketch, but its structure is familiar enough. It’s basically the same joke as the classic "Miss Triggs" Punch cartoon. In both cases, the joke is funny (in a rather painful way) if you recognise the situation, and not if you don’t. Miss Triggs would be baffling to someone who was oblivious to workplace sexism, I suppose.
Recently a Japanese Youtuber did a vox pop in which he asked Japanese people to react to the sketch. The result was fascinating. (If you don't have time to watch the whole thing, skip straight to 4:15.)
Yuta the Youtuber was surprised (and so was I) that so many of the Japanese people watching didn't get what the sketch was about. Of course, that just underlines the point of the sketch.
But what was the point of the sketch? Was it about Japanese racism? Those are the terms in which many commenters view it, and it's easy to see why. The waitress is treating people differently according to her race-based assumptions about them, after all. If the Miss Triggs cartoon is about sexism (and it is) then by this must be about racism, right?
But one difference is that the men in the Miss Triggs example have seen women all their lives. They have had ample opportunity to notice that women are capable of intelligent suggestions - Miss Triggs’s is just the most recent of many they must have encountered. In Japan, by contrast, Western-looking people who speak fluent Japanese are pretty rare. (In many parts of the country Western-looking people are rare altogether.) Not expecting Westerners to speak Japanese reflects their lived experience.
Even so, the people in the restaurant give ample proofs that in this particular group the Japanese-looking woman cannot speak Japanese, and the Western-looking people can. Despite this, the waitress persists in her error. Isn't that racist? Or is it more like the kind of playing card experiment Bruner and Postman famously conducted in the perception of incongruity, and which you can enjoy here courtesy of Interstate 60?
“If you do the test again, you’ll pass,” says Dr Ray. Perhaps that’s the real test?
Well, I end this post rather stutteringly because I haven't really come to a settled conclusion about all this, but I'd be very interested in your views on the relationship of racism, Bruner and Postman, assumptions based on past experience, etc.