The sitter is depicted as Saint Agnes, patron saint of virgins and young girls, with her attributes of the lamb and the sword. The sitter may also have had the Christian name of Agnes.
The silver support and the delicate finish suggest that this was a precious object, perhaps painted for a loved one or husband to carry with him. It is possible that the sitter was a member of the family who later bought the property.
The background portico resembles the one designed by Rubens for his house in Antwerp.