I saw the presentation, but I just don't get how she was doing that to purposefully appear "cute" or could it have just been out of a combination of excitement and nervousness.
I really don't know what you get out of denying she was flailing her arms and exaggerating her words and movements to appear cute - like, she herself was doing it.
If she wanted to be serious she wouldn't have done those 'spooky' and 'Mite ne!!' bits.