There is demonstration of how Peter feels about Harriet which is mostly skimmed over or ignored in the novel; in the television adaptation, you see him touch her, more than once, but always in circumscribed ways. They dance in the novel, but the actors show desperation in the way Harriet pulls away from Peter before the dance is concluded. A lighthearted discussion of marriage proposals becomes less lighthearted, and Peter's joking hand on Harriet's knee attains new significance. In the final scene, Peter takes Harriet's hand and kisses her wrist, between glove and sleeve, a deeply sensual gesture that shows us all we need to know.
There are the usual minor changes to the novel. The only one that really disappointed me was riding the horse down the beach--Bunter replaces Peter, which may have been a matter of the actors' riding ability, or simply that the available stuntman had dark hair. The casting is good. Jeremy Sinden as Henry Weldon is wonderfully odious!