To my mother, Angela's Ashes is about Ireland. Gone with the Wind is about Georgia. Where the Wild Things Are is about where the wild things are.
To me, Angela's Ashes is about Frank McCourt. Gone with the Wind is about Scarlett O'Hara. Where the Wild Things Are is about Max.
To a lot of people, all of the above are about what happens next.
It's an oversimplification to say that any of us is solely a character reader, a setting reader, a plot reader, or any other kind of reader. Even I admit that Make Way for Ducklings is more fun if you know your way around Boston, regardless of how cute those alphabetical ducklings are. But we all have things we tend to notice when we read, and my experience with a particular book is probably different from yours with the same book.
That's why I love selling books when the recipient is actually present. When I'm talking to the parent, I can get some helpful information from the answer to my first question: "What's another book (s)he really likes?" But when the reader is there, I can get much further with Question #2: "What do you like about it?"