I wondered about this too for a long time, but never got to think it through. (So, naturally, I stopped reading the article half-way through to try and figure it out.. still on it!).

A small request: the photo on that page is a 10MB, 16MP image displayed at 600px x 600px. It took a noticeably long time to load on my current connection.

You can resize it and shrink to under 100KB without any visible loss in quality, making the page way snappier to load (and more accessible to people with slow connections).

Thank you again for an interesting article!