guess Maki's not a really effective charger then..
That's their "dere" battery; it can only be charged by the "dere mode". Maybe someday Nico will be able to charge hers from Maki. ... and maybe hell will freeze over, too.
Researched it a bit, and it turns out there were 2 visualnovels released with the later BDs of the show. There is a scene in one of these where Tougou wears a costume like that. No idea about the context, though.
My first instinct is "Yes", but it's hard to tell... Since there's nothing we can see that defines her as Miku, and the pixiv isn't tagged Miku or Vocaloid, I guess it's original.
Actually, glimpsing the calander behind Kyouko, it seems Kyouko does most of the cooking. At least Fri/Sat. I suppose if she is going to eat most of it, she should make it...
Here we see Flandre engaged in a post-coup ritual asserting dominance as she takes control of the pack. Also, Remi looks comfy. Just look at Flan's contented face.