We haven’t seen Rukia in a Box have we? Maybe we have, If you remember the Lost Shinigami Arc, we saw that Rukia was captured and put into a Dollhouse where she had to battle Riruka Dokugamine. Obviously she was attracted by the cute things in that small box but got into the mood to fight when Riruka made her serious about the fight.
I feel that the artist had drawn Rukia specially to refer to this specific moment with Riruka Dokugamine. Although it was a short fight it was still a memorable fight between the two. They had a good fight, plus the whole Lost Substitute Arc ended with Riruka escaping and going her own way.
The artist also has some other Bleach characters drawn in a box, Ze-RoFruits has drawn them with a unique twist, the colours are vibrant and come to life. Check them out.