This was superb, mind that the pacing was secondary to the photographs and layout. A photographer or artist story about what you see within the frame, no surprise.
Everything worked nicely up until the epilogue / volume 2 bonus. That was cute but nonsense.
In the original ending, Amane proposed the relationship but only said "I have a great time when we're all together", not that she was in love with Kou. Kou's slightly excessive concern for what Amane thinks bothered me until Amane noted that "Taru-Taru loves both of us". I hadn't caught that how Kou looks at her models in an identical way, and similar to how the manipulative senpai thinks about Amane. I only noticed Kou had the potential to fall for both Amane and Nene, and she fell for Nene quickly when confessed to, but not that she already loved both her models. Everything came together into a believable aysmmetric poly relationship where Amane hasn't thought about Kou much yet because she spent the full story pining for Amane. By the time of the wedding pictures long afterwards, maybe Kou fell in romantic love, maybe not, either one could be healthy.
The epilogue doesn't have a location in its background, so it could have taken place any time after the ending trio started dating. It's far enough out that Amane's feelings could have grown deeper. But without buildup, no clues for the timeline, and being the sort of question she'd probably ask very soon after the three started dating, it felt rushed. It's fine but, with this author, two chapters leaving Kou with a sadder position might have been more satisfying than the finale and epilogue being this disjointed. It was just a slapdash publisher-requested feel-good fluff extra.