You don't just plop down and meditate! Not unless your mind is very, very empty to start with. (Is that even a good thing?)
No. When you sit to meditate, you cycle through several predictable mental states, with a multitude of sub-states in each. The graphics show you what you can expect, and give you a "roadmap" to help you manage the process.
The detailed writeups that accompany the graphics, meanwhile, (8 pages in the PDF version!) dive deep into the meditation process, helping you to understand what you are likely to experience, how to deal with those experiences, and why you want to meditate in the first place!
Most importantly, once you know you'll be cycling through these states, you won't try to do something non-sensical like "stop thinking", and quit kicking yourself when you can't.
And you may find that rather than being a distraction, some of those "thinking" states could well be some of the most productive parts of your day!