I did see something about this. If I'm honest, I haven't been overly keen on some of the Beeb's recent efforts at adapting novels or their making of historical drama. I've not read any of Daph's books, but have read plenty of 19th century authors, and she probably harks back to those days. Hitchcock must have liked her stuff as he did Rebecca,, though it was Selznik who chose that to film, and his last British film Jamaica Inn, with Laughton and Newton, which I call the battle of the eyebrows.
I think Charlie's eyebrow in this shot is off to find the nearest leaf...