Capt W's interest in Anne seemed to increase each time he noticed someone else appreciating Anne's looks. I have the impression from something Lady Russell says that Anne resembles her mother; as vain as Sir Walter is, I have always assumed that Anne's mother was pretty, although in a quiet way (so as not to compete with him). Lady Elliot has been dead long enough to be considered a neglible issue to Sir Walter, so his idea of good looks is hinged to his own appearance (IMHO).