I know this thread is dead and all, and has already, for the most part, been a suffice enough explanation to that nagging 'what-if' you had in mind, Zeraph... but I still found it curious that I just came across this.
In my own estimation, this is a portrayal of what the impetus, and action thereof,
a true 'nyah' moment comes into its own, and presents itself (in reality)...
(notice the 'eye pull-down', an extended and jutting tongue being directed at you,
and as it all comes into place, at the moment it happens, can you honestly and
actually hear that distinct 'nyah' sound emanate from her. It's a Japan/Korea/manga/anime/catgirl thing ;
I don't full get it, I do realize it is used as a "playful" insult or reactionary pose for those that have mistreated the perpetrator of this pose.)