[ProgramMax]

Yeah. I mentioned this elsewhere but repeating here:

I designed the article to be accessible and understandable for the average person. So I took some liberties like showing only HDR primaries and not deep diving into HDR transfer functions. People understand the primaries intuitively.

But you are right that a wide color image could also use those same primaries without being HDR.

My goal was to be as truthful as possible while still being digestible at a glance.

In the article, I linked to Chris Lilley's post which explains it more thoroughly for the technical people.