Nanachi's little hovel is so cozy it's insane. I love that it's SO domestic despite being essentially a cave/treehouse built from trash. It's tasteful but also clearly ramshackle. It's green, so it's got that natural, soothing feel that some hospitals go for by painting the walls green. It feels like a homeless encampment but also like a place that's well-cared-for. It's got these artifacts and relics gathered in it you wouldn't find anywhere else, and it's the most civilized spot in where it's located, but it's also someplace primal where someone who is like an animal sleeps. It's halfway between a bedroom or a dormitory and caveman-tier hole-in-the-wall.
This and the seeker camp have this vibe to them that's just... Wow. Worldbuilding like this is something special and I love how much is communicated visually. Nanch's spot just FEELS warm and cozy.

Explain this image to someone who doesn't know Made In Abyss