I've had this on the tip of my brain for a while, but I'm finally putting words to it. One of the themes of this story is "The anxiety of growing up." Growing up can mean the uncertainty of independence, the wild risks of the heart, or adulthood = sexuality = abandoning your youth. Nostalgia is often the comfort of the known past contrasted with the discomfort of the unknown tomorrow. A lot of Chokki-chan's "Romance" is childish nostalgia; Stick collecting, finding wonder in wandering about, believing in cryptids, etc.
There's still hints of something in Chokki's past that she's afraid of. Dreams of a home, clinging to her childhood, and such. Possibly a divorce? Her childish whimsy is the biggest obstacle to realizing her feelings for Shun.
This chapter really helped cement those themes. She wants to capture their youth, but on a camera that has no pictures of herself. And the photo they got was clumsy, accidental, a learning experience. But instead of a planned picture of just her, it was a picture together. UGH MY HEART. I said it in chapter one: "This has a blend of sweetness and ennui that slaps." Forge your future together, you precious peanuts!
