Why were Rembrandt’s tronies not intended as portraits?

Rembrandt’s tronies were not intended as portraits because their primary purpose was to depict single figures in historicizing, imaginary, or exotic costumes to represent specific concepts or themes rather than to capture the identity of a specific individual.1

While real people, including Rembrandt himself, served as models for these works, the focus of a tronie was on the expression of qualities such as piety, soldierly bravery, old age, or the representation of distant cultures like those of Asia or the Middle East. By utilizing these stylized costumes and settings, Rembrandt used tronies to explore artistic themes and character types rather than to fulfill the traditional function of a portrait, which is to provide a likeness of a specific person.1