It's not so much the medium, but the style he writes in. And don't worry, it can be hard for even Japanese people. This one is pretty easy for me because I'm adult with lots of experience, but my kid in 3rd grade probably wouldn't be able to tell.

Seriously! Even after knowing what it is, I look back at the picture and can barely see any hint of it.

The flip side though is that once you get good work kanji, you can also be very expressive with them in ways not really possible with a phonetic script like the Latin alphabet :p