I think it is a little different than smalltalk. When people smalltalk, no matter how shallow the conversation is, there is still an intention to “get to know” with each other. But in the cashier example, the cashier does not have any goal to forge a relationship with the customer, but will repeat the same thing over and over because that’s what they’re told to do in the manuals.
No. Small talk is, by definition, incidental to the functional, "business" parts of the transaction. It excludes things like: "Your total is $X". "Out of the $Y you gave me, your change is ..." -- i.e., the things the GP was describing in Japan.
Edit: "Welcome to the store [some mini sales pitch]" might count as small talk, but is not what most people have in mind.
The difference would be that it’s one sided, there is no expectation of response.
It’s so funny when sometimes the clerk has been doing it that job so long that it’s not proper words anymore and you’re not even expected to parse it correctly, it just doesn’t matter.