These are the artwork names and descriptions, in order of appearance:

• Sekibanki and Kogasa. Both of them are depressed, but while one of them chooses to display it in the form of angst, the other hides it behind a playful appearance.
• Eiki and Youmu. Happy Youmu and Eiki day!
• Portrait of Wakasagi-hime. Eyebrows exist to keep water from dripping into the eyes of terrestrial animals, which causes their vision to blur. Since fish already live in water, they have no need for eyebrows. Or hair, for that matter. If fish had eyebrows, I probably wouldn't fish.