The point I was trying to make is that the text in a programming language like Python is like a visual diagram of standard control flow mechanisms. I can see the for loop, what it iterates, and what the body of the iterator is. The language has visual clues. And with syntax highlighting it's even more visual.

But, I get that there is a class of visual languages, often dealing more with interconnected nodes like a directed graph, for which graphics might be better at communicating. But they seem more domain-specific rather than general purpose programming (like most text languages).