The only thing I can remember from my PPL GFT in 1968 was the Examiner advising me ALWAYS to check that the 'passenger' had actually strapped in! He'd obscured his (unfastened) seat belt with his arms to make the point.
On PPL Skill Tests, once we were in the aircraft, I would explain that I was to be thought of as a (reasonably) intelligent passenger who wouldn't ask silly questions, but would point out any aeroplane he saw. On the first navigation leg, all I wanted to know was the ETA at the turning point (with any update) and, if we were off planned track, I'd just want the pilot just to describe what he/she was doing to sort things out.
"If I don't say anything, I've probably just fallen asleep!"
For the 'emergency brief', I would expect something clear and simple. If the pilot launched into a full "Welcome aboard this PA28....." speech, then I would just let him/her get on with it - mainly so that they felt they'd earned a smartie point. But then I'd explain that, as I was the actual Commander, if anything actually went wrong at a critical moment, I would probably take control using the executive words "I have control" - but my intentions would be exactly as the pilot had described.
All those flying a PPL Skill Test should remember:
We've all had to do it ourselves.
There'll be nothing in it you haven't done before.
You wouldn't be doing it if your instructor didn't think you were ready for it.
WE WANT YOU TO PASS!