Maxi's going back to her room is at this spot but the reason is a bit different. In the story, she ate along with Riftan and the knights earlier. She got the feeling the knights didn't like her. There was a reason for that because her father treated them poorly so their disrespect for him rubbed off on his daughter. So, she felt like her position in the household was weak and she could be abandoned.
By this time in the story, Maxi left because the conversation was heated and it put her off too much. Also, she was upset to think that Riftan was going to leave.
So, it looks like they tried to put these two things together in one go. In the story Riftan and Maxi had sex a few more times by now and he's had the chance to tell her in words that he considers her desirable and acts towards her like a true husband. She's already warmed up to him more than what's shown here.
***
The conversation at the end is actually two in the story, the first was a little more mundane. She asks about the sword and he says he won it at a competition. She says mostly the same lines as here. But, Riftan just says it doesn't happen like that. He wouldn't want to get a kiss from a stranger anyway.
The second one is right after this dinner argument. That figurine is a sample. Maxi asked if Riftan thought her choices were okay but he was like "do whatever". He tells her he wants her to be in a pretty dress, and then tells her about the trip he'll be taking and that he'll bring her gifts back,