Is there a way to tell what type of picture I am watching. I've read that a lot of TVs pop up and tell you or have an info button tell you but nothing happens on my Q8F.
I can tell usually because the back like ramps up to 20, by default on normal content it's lower than this. So if you go into your picture settings when playing HDR content it should ramp the brightness up to max.
Note that a lot of YouTube footage claiming to be HDR seem to be copies of demo clips re-uploaded and have lost the HDR meta data.