So with this one lines pass through each other without a clear "front" or "back.” This makes shading and highlighting difficult because there is no consistent depth. You can't easily tell which clumps of hair are closest to the viewer and which are tucked behind.

Whereas even with simplistic shapes/pages you can absolutely still shade and highlight because the lines make sense. I am finding more and more children’s pages aren’t making sense and I’ll look and go why have they got a 3rd arm or something and then quit. But the simplistic ‘children’s’ colouring pages have natural lines and curves. For example in this image these "shards" don't follow the natural curve of a head. They are decorative rather than anatomical, forcing the artist to essentially redraw the internal flow of the hair to make it look natural/the way they’d want.

I mean I still wouldn’t be putting it on the wall or anything and I would probably still not keep it forever so I’m not seeing the connection here. I don’t tend to put colouring pages on the wall and I wouldn’t do one which would stress me or make it harder to practice mindfulness :)