I think I feel dumber for reading this. (The referenced paper by Ousterhout is quite good though, and doesn’t confuse the terminology. Maybe that one’s what HN should link and discuss.)
There are a few bits that don't make sense eg cookies where the server sends something and the client is expected to remember it but they can just be ignored.
Also, as a minor point, even when browsing the web, a minority of the actual requests deliver HTML -- most of them are for various kinds of media referenced by the HTML document.