As an example see: Three Needlework Samplers: Martha Platt (1815-1887), Mary Ann Goodrich (1806-1828), Louisa Bradley (1802-1830?)]
It shows genealogical information about the item, including sources, and historical background information about the people and the area (Litchfield, Connecticut).
I stumbled across this by accident. I don't know how to find more genealogy information on the Sotheby's site.