Go Jia's hair

I hadn't noticed this until my girlfriend pointed it out while discussing going for the Wei true ending in our respective runs...what's keeping Guo Jia's topknot holder on?! Normally, you'd expect to see pulled-back hair for a topknot keeping it in place (like Cao Cao has, e.g., pic 2), but Guo Jia just has a normal mid-length men's cut all around, parted down the middle...you can even see hair coming out and hanging down from under the topknot holder! And it's even got the pin through it that would hold the hair in place! Either the dude has a tiny bit of very long hair in the very middle of his head clinging to his headpiece for dear life, or he's using some Zhang-Jiao-ass magic to keep that shit in place.