What do the shapes mean?
I prefer the rules in my copy of Design Elements - A Graphic Style Manual. Its rule #2 make a comment that is apt here: communicate don't decorate.
"How many UX concepts can I attempt to illustrate with basic shapes and shading?"
If it were meant to convey information first, it would have looked like this: https://news.ycombinator.com/item?id=24031163.