Marianne’s sexual proclivities have a slightly different treatment in the book as well, where word gets out about the images. The issue of consent is far murkier here, since the book doesn’t depict Marianne straightforwardly asking for a dom/sub relationship or a clear violation of those boundaries, but rather an entire relationship built on the idea that Marianne is punishing herself for not being worthy. There’s little exploration of what, if anything, the photographer thinks about all that, though it’s hinted he was at least somewhat opportunistic about the whole thing. The Sweden trip also happens just a bit earlier in the book, helping set up the tweaked ending.
One major difference is that we don’t know much about Marianne’s life at this point, so it makes her decision to stay in Ireland feel strange, or like a manufactured obstacle to contrive the weepier ending. On the other hand, in the book, Marianne has a career of her own and an entire life that she’s fought hard for, independent of her abusive family and the toxic members of her college friend group. Another is that Sadie, at the literary magazine, is a bigger character, as is Connell’s sex life with other women in general, so the possibility that he might be in love with Sadie or just sleeping with her feels like a real possibility to Marianne, if not the reader, just like Helen once thought about Marianne herself.
While a list of the events that end both the show and the book would probably be nearly identical, the tone is quite different. The same lines of dialogue, such as Connell saying he wouldn’t be here if it weren’t for Marianne, reads completely different in the context on the page, where it feels like Marianne is owning some twisty role in his life that she’s almost ashamed of, versus on the show, where it’s Connell acknowledging the gift of helping him through his depression she gave to him.
The show ends with Marianne sending Connell off onto his great big New York adventure with a wistful, loving mood, trying to be realistic about the fact that their lives are truly diverging for the first time. It imbues the rest of the show with a feeling that it’s a story of the place a formative first love can have in your heart, the way they can change you forever and always be special to you, even if you ultimately part ways.