Do not attempt to mix these kinds of prints at home, you’ll probably wind up with a blinding mismatch.
So how does Dries Van Notten make this work?
I think that in addition to similar print proportions, it’s the colors.
Here’s the point. Sometimes, you have an instinct that tells you something works, even though it breaks every “rule” you ever heard. If you parse it out, you can find out why your instincts told you what they did.
Or you could just follow them. It all depends on how accurate they are as a rule.