Mrs. Astor's plush horse

Mrs. Astor's plush horse

old-fashioned Someone dressed or decorated very ostentatiously; one who is particularly pretentious or showy in appearance. Look at her swanning about in all her furs and jewelry. Who does she think she is, Mrs. Astor's plush horse?
See also: horse

Mrs. Astor's plush horse

Ostentatious. Mrs. William Astor, the leader of New York society at the end of the 19th century, was not one to spare any expense in clothing, furnishings, or other accoutrements of the Good Life (so much for the idea of quiet old money). Her appearance and her gala parties were so sumptuous and well-known that anyone who appeared dolled up beyond normal was ridiculed as “Astor's plush [or pet] horse,” as if the formidable Mrs. A had lavished her wealth on that person as she would on a favorite plaything.
See also: horse