Being tangible

The Tangible Kingdom is a new(ish) resource from a site called !! The Tangible Kingdom. There's a book which has received quite a few kudos, and you can see a 'remix' version of it here.
I personally didn't find that particularly helpful maybe because I didn't look at it carefully enough, but there's also a video:



The video is slow and quiet, and takes a minute or so to begin to make its point, but it does make its point - by using one neat symbol.