> not a very simple one with all the "labels" and "numbers" etc.
I understand this concern. I did have quite a large number of non-technical people do the Japanese version of this course (I have a big following in Japan), and they seemed to actually understand it based on the feedback I got.
The course itself doesn't use any code and is not very fast-paced compared to this article: it spreads out the material covered in this article in 17 pages and takes about 2-3 hours to read.
> I wonder if this visual presentation of lambda calculus is your invention
It's my invention (spent a year tweaking the details) but was inspired by things like Scratch. https://scratch.mit.edu/