Non–Linear Book Reading Experience

I started to play with a non-linear book reading.
Starting with just a high level extract, you'll read deeper only into parts you're interested in or care about.

Of course this is not applicable to every kind of book, but just imagine what if we wouldn't have to read text linearly/serially anymore?

See example: Elon Musk by Ashlee Vance
Spoiler Alert! If you haven't read the book, do not click.