Nin is both Bluecher and Hipper's character designer and official artist, and this is highlighting his imagined differences between them. Not official art, but can probably be taken as something close. I do wish we had a tag for "art drawn by official artist in unofficial capacity."
I tried translating some of his comments. Just from what I can gather, I find it cute how Blücher likes and imitates her older sister, and how Hipper seems to cares for her even without outwardly showing it too much.
There is a grammar mistake in Blucher's 3rd bullet point, the artist writes 何も which should be either 何もない or 何でも, meaning nothing and anything respectively. The artist has 中国語OKAY、英語OKAY、日本語もOKAY、GRAMMARは全然ダメ。in his twitter bio, so it's not surprising to see a mistake.
some kind of hair style/weaveResistant to heat.
Also resistant to cold.Angry look
Tsundere; 8:2::tsun:dere
Worries about her little sisters
Has many hobbies
Glasses (hides that she wears them)Linepen
"line pen" is another name for a marker in JapanEnergetic 9/10
Receptiveness is one of her strengths
Interested in everything
Loves her sisters and the commander4'9"War machine model
not that warmachine, right?Scarf:
A present she received from Hipper in her launch dayHer older sister's clothesHipper & BlüHelmet5'1"For indoors
