A book gives more detailed psychoogical characteristics and on the whole a larger picture than a screen adaptation does. However, it's easier and faster to learn the whole story, especially if the book is long.
In P. G. Wodehouse's Jeeves and Wooster stories there are those kinds of quick and precise portraits.
Honoria 'had a laugh like waves breaking on a stern and rock-bound coast.' -- Nice metaphor. And in the film Honoria's laugh corresponds with this description.About Jeeves. 'Cold and haughty, no symp. None of the rallying-around spirit which one likes to see. As I had anticipated, the information that we were not going to Monte Carlo had got in amongst him.' -- The characteristic of the person in a certain mood and knowledge is shown in these lines.
The description of the voice. 'This one was something in between the last Trump and a tiger calling for breakfast after being on a diet for a day or two. It was the the sort of nasty, rasping voice you hear shouting 'Fore!' when you're one of a slow foursome of reared colonels. Among the qualities it lacked were kindliness, suavity, and that sort of dove-like cooing note which makes a fellow feel he has found a friend.' -- That's a vivid description of the feeling on meeting a friend and not a friend, through contrast. "...kindliness, suavity, and that sort of dove-like cooing note which makes a fellow feel he has found a friend." -- That's it.