I was looking through the link @s0ewhat put in the charlotte general discussion:
and this one image really caught my attention:
The reason I was shocked is not only because of how adorable Nao looks, but of how joyful she seems.
She is normally quite serious and stern about everything so I was thinking maybe she will change now that her brother has returned. Or it could only be one of the rare moments where she shows exitement towards something.
Regardless of the reason, it is nice to see a smiling Nao.