Who is Scrope Purvis, and what words and phrases does he use to describe Mrs. Dalloway? What does this description reveal about Mrs. Dalloway?

From the text:

A charming woman, Scrope Purvis thought her (knowing her as one does know people who live next door to one in Westminster); a touch of mangonel bird about her, of mangonel jay, blue -green, light, vivacious, though she was over fifty, and grown very white since her illness.