I barely know anything about Japanese, but the text seems to say "What are you staring at?". Because I'm not confident that I actually understand it, I'm only posting it as a comment here, and not as a translated text box thing, if you know what I mean.
I think the commentary is saying he hopes this isn't the last picture he gets to upload this year (because Miku won't pose for any more if he answers her question)
I'm sure I've seen girls do that pose before. I do agree with you though, OOZ662. Just seems like one of those poses that's not natural unless you've been doing it already.