Anybody read the book? serious miscast

Hello, the book by Ruth Rendell explains it (how did philip get step by step into this situation, etc.) but: serious miscasting in my opinion.... Senta is supposed to be tiny with silver hair and philip very tall, towering over her....) I don´t really like how Senta is "bigger" then philip... not only her body but her face as well....
everybody has a different taste and likes, but I did´nt expect this, after reading the book....