What is the mirror of the soul?

Mirror of the Soul

ut imago est animi voltus sic indices oculi

the face is a picture of the mind as the eyes are its interpreter

—Cicero

The spirit is reflected in the body, and although the body is only matter, yet being modelled on the capacities of the spirit, the latter impresses upon it a certain character that is more particularly visible in the face, especially in the eyes, which have been truly declared to be the mirror of the soul—

The face reflects the soul more especially than does the rest of the body.