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.

Hipper secretly wears Glasses

Cute.

T34-38 said:

Cute.

We need that as a skin *now*

Blucher is honestly really cute. I can't wait to get her.

T34-38 said:

Cute.

I have the strongest urge to give her a ring now.

IndustriousMechanic said:

I do wish we had a tag for "art drawn by official artist in unofficial capacity."

We have one now. pool #19122.

VR-Man said:

We have one now. pool #19122.

Thank you for pointing that out - I'll have to go through my uploads again.

First looking : "Hipper Retrofit yeahhh"

Wait, Hipper is 146cm? She's legally a midget.

Cleaned up translation. Biggest point of confusion seems to have been the note at ~1 o'clock position. Seems like it is referring to her clothing, not her hair - woven, not braided.