The "hmm" animation long, long predates Viera/Hrothgar and possibly even Au Ra, even though it's only become a player-accessible emote recently (and I will forever hate that giant glowing question mark). I'm fairly sure we've been doing it in cutscenes since ARR; certainly since Heavensward.
I made a post a while back asking whether it was an emote, and took these screenshots as example:
Female Midlander and Roegadyn have very different poses, and (having since added Miqo'te to my character collection) I can say that the male Miqo'te pose is not the same as Au Ra's even though they are similar.
There are only so many ways you can do an "I am obviously thinking hard" pose.