Hi, yeah, me again, ruminating this time on pov and how cleverly you use Snape's "obliviousness" to make an enigma of Minerva. Aside from wondering whether she expects him to pay and if she's going to throw him out on his ear, Severus doesn't really speculate about Minerva -- what she might want or need or why she might do what she does. She's still an "adult" to him; he seems to look at her the way a child does a grown-up (especially a child like Severus, who never had adults put his welfare/happiness first) -- as an inexplicable, often capricious being who wields her considerable power in either arbitrary or needy (like his mother) ways that he's given up trying to make sense of; adults just do what they do, and he'll respond when he needs to and otherwise will live within himself when he can. He scopes out Minerva's bedroom and photos not because he's interested in her, but because it gives him a power of his own.
His indifference becomes a bit chilling, of course, as we see with his response to finding her sobbing over the Prophet and his complete lack of curiosity about what might have happened to Andrew. But if we try to think of Minerva outside of the narrator's view, she seems less Eileen-user-like and comes across as a perceptive, generous, powerful, self-contained, butterfly-collecting (with all that that detail implies) woman who has opened her home to two damaged men, and herself to one of them, given them plenty of space, helped them save themselves (or at least not destroy themselves), and got some pleasure out of it herself in the process. No wonder she says she's had a "lovely holiday."