I feel like at 6 years old you understand enough to describe state machines.
I did this when I was 6 with the older lego RCX brick. I didn't understand the limitations of the graphical programming language at the time because nothing I thought of was complex enough to push them. It still probably helped me understand intuitively how "dumb" computers are which can be pretty hard for beginner programmers to grasp for some reason.
> It still probably helped me understand intuitively how "dumb" computers are which can be pretty hard for beginner programmers to grasp for some reason
Grasping the dumbness of computers can also be done via a bottom-up approach: transistors, then gates, then boolean-logic/state-machines, then binary-numbers/ALUs, then processors, and so on. "You think it can do X? Then show me how that could be built, using what you've learned so far!"
(Analogous, of course, is learning mathematics starting with a 3-column-proof-based approach, rather than ... err, whatever they call the typical American approach.)
I did this when I was 6 with the older lego RCX brick. I didn't understand the limitations of the graphical programming language at the time because nothing I thought of was complex enough to push them. It still probably helped me understand intuitively how "dumb" computers are which can be pretty hard for beginner programmers to grasp for some reason.