> I like the conversation about web performance, but you should make sure you practice what you preach
I'd say the author is practicing what he preaches, the JS is just 4,6 kB.
There is some optimizations [1][2][3] that can be done to the images but I wouldn't fully disqualify the article because of that.
The websocket connection is kinda odd though, I tried reading the code but didn't fully catch the purpose, it just says something about pointers.