these two sample images are from a doujinshi sales website.
I would love to see more of Murai Shinobu’s doujinshi someday,
her Celestia & Luna art & comics are probably my favorite interpretation of the relationship between the Sun & Moon alicorn sisters,
in terms of both art style and mood.
In Murai Shinobu’s comics,
Luna tends to enjoy intimidating or teasing Celestia in private.
Or at the least,
she tends to be in charge socially when its just the two of them.
Not that its entirely one-sided.
Celestia is just very patient with Luna’s behavior,
and knows how to calm her down if necessary.
Basically, I’m guessing Luna is purposefully trying to spook her elder sister here.
Edited
‘And if it’s night…’(それに 夜ならば)
Hmmm, It looks like Lunas slide towards the dark side.