What kind of “engineers”? I’m not aware of most engineers going through this sort of interview. Mostly just software engineers who are indeed programmers even if they get uppity about the title
OK, I'll play. Some qualities that are valuable in an engineer are curiosity, creativity, and general knowledge. If your nomenclature has a programmer as a software engineer and a software engineer as an engineer, then these qualities are also valuable in programmers.
If you ask an interviewee how GPS works and he says something about the cell phone sending signals to a satellite, you would want to pursue that further, at least to make sure that he's asserting that with a sufficiently low confidence.
The thread became about whether a good interview question for an engineer was how she thought GPS works. HeyLaughingBoy thinks that the qualities a question like that seeks to explore are irrelevant for a programming job.
I think that it is a good question for any engineer. One explanation for why HeyLaughingBoy might have disagreed was that HeyLaughingBoy was making a distinction between a programmer and an engineer.
I thought that highlighting the distinction between what HeyLaughingBoy wrote (programmer) and the parent (engineer) was a parsimonious way of expressing this.