Symbolism, Imagery, Allegory
Giving gifts is often a way to express affection or social obligation. For instance, Char catches a centaur and gives him to Ella in order to show that he likes her and thinks she'd be a responsible centaur-owner (however one goes about that). Hattie and Olive each pester Ella into giving them "gifts" on the carriage ride to finishing school as a show of good will, despite Ella's unwillingness to be a part of that transaction.
Here's the thing about gifts: they're not always nice. Take the very first gift we see: Lucinda's. "My gift is obedience," she says. "Ella will always be obedient." (1.1)
Thanks a lot. This is a good example of how a gift can sometimes be more about the giver than about the … gifted? Giftee?
Anyway, the point is that Lucinda wasn't thinking about Ella when she gave her the gift. (And we have today, was Char really thinking about Ella? What in the world is she going to do with a centaur?) Sure, some of the gifts seem unselfish—or, rather, we can think of one: Mandy's fairy book. Other than that, we have to say that all the gift-giving seems a little one-sided, almost as though it's a symbol of how so many people seem to lack basic social skills in Ella's world.
We're not saying everyone's irreparably selfish or anything, but it's easy to think of what you would like when picking out a gift for someone else. Don't try to protest that you've never done that. We know you have. The characters in Ella Enchanted, no matter how thoughtful, are often guilty of the same.