It contains lovely double page spreads showing screenshots from a whole bunch of popular NES games, with a bit of info on each title:
There are various mini-features and articles on other aspects of the system, such as the R.O.B peripheral and the physical hardware, along with exclusive interviews, fan art, and more:
And there’s even some gorgeous game box-art images too:
It really is a work of art itself, and if I had the money I would definitely buy a copy; it’s absolutely lovely.
You can find out more details about the book here if you are interested.