The difference in expressions between the two royal guards when perceiving a possible threat
Even among the ever loyal royal guards of the chimera ant king there is a difference in personalities. Shaiapouf is the serious one, very analyzing. Neferpitou on the other hand can easily be distracted and always on the alert for something amusing to do.
The third royal guard, Menthuthuyoupi, is someone who really doesn't give much thought to things, but relies on his brute strength.
I'm quite envious of Pitou's personality. I'm sure she never gets bored.
In the end, I think only Pouf's personality remained unchanged.