you're seeing the tree and missing the forest -- this isnt about the examples its about the technology they feature. write a LOGO turtle example, then you can scrub its instructions, and execution
Would it be cool to have this "at large" for a full stack of software. Possibly, but I'm not completely convinced yet.
Edit: Seeing how you can "slide" numbers is also kind of neat, but again, I'm not sure it really helps understanding. If anything, I would think this is somewhat confusing, as I have to grasp changing the numbers treats is as if that number was changed on previous iterations.