From what I remember from long ago schooldays, in the book the novelist was the all-seeing eye who made comments and told us what went on inside Lily's head. Whartonites who are tolerant might not object too much, but exacting Whartonites will. The larger problem is the filmization of good or great novels. It's a no man's land strewn with mines. Think of it.
Examples abound in all categories.
From solid literature to classics, faithful and good adaptations are rare. Or else the quality of the resulting movies is such that cuts, changes and infidelities don't affect movies that are filmically impressive. And of course there's the large number of pictures that have only bare-bones connections with the source stories, but succeed as a different medium. Not the irritatingly vague Lily, not the hazy male or the incomplete supporting female roles. Not even Eleanor Bron, one of the movie's rare non-American performers.