In what seems like at least half her novels, Agatha Christie writes that one character waits for a "minute or two." At first I thought that these characters were actually sitting there and pondering, mid-conversation for a full 120 seconds while the other character was staring at them expectantly. However, this phrase has also been used in situations of high urgency, so I'm starting to think that "minute" is actually just being used to represent a pregnant pause.
Tommy became restive. The conversation he had overheard had stimulated his curiosity. He felt that, by hook or by crook, he must hear more.
There was no sound from below, and it did not seem likely that the doorkeeper would come upstairs. After listening intently for a minute or two, he put his head round the curtain.
In this passage, Tommy is considering moving closer to eavesdrop. Waiting for a full minute would sort of defeat the purpose!
My questions are:
Am I right about this meaning "a moment" rather than "60-120 seconds"?
Was this something actually used by many writers or speakers at time, or is it peculiar to Christie? (who, in my opinion, writes some of the most incredible plots and characters, but her prose feels a bit amateurish, which might explain a "mistake" like this.)
When and why did this usage fall out of use?
Edit: I don't agree that "He waited for a minute or two" is the same case as "Give me a minute."
For example, if someone expected to take another 10 seconds to finish something, they might tell you "Give me a minute", but more likely, "give me a second." However, they would most certainly not say "Give me a minute or two" because that strongly suggests from close to a minute to a few minutes.
In addition, I am asking much more about the specific phrase "minute or two", which she uses exclusively. Characters never wait for "a minute" or "about a minute."