Just a random guess, but I could see the argument that it would reduce crash bleed into the rest of the kit. It might make it easier to mix the main kit more tightly. But if that’s the case, then why leave the hihat low? It might just be a stylistic thing or it might be for the drummer to remember to not ride the crash. I dunno. It’s certainly not standard. They’re the only ones I’ve seen do it on such a small kit.

Edit: I just realized it’s probably up so high so the drummer doesn’t accidentally kill their pollinators