#3. An image participates in the reality to which it points.
See the first chapter of Charles Williams' book, The Figure of Beatrice and Dorothy Sayers' notes to her translation of the Divine Comedy, especially the Purgatorio.
Beatrice was a real Florentine woman (her identity), an image of beauty.
#300
Beatrice is beautiful,
A woman fair of face.
In Dante's poem, an image
Of beauty, faith, and grace.
Beatrice is thus an image of at least 3 qualities: beauty, faith, grace. More women than Beatrice are beautiful; more people than Beatrice have faith; more people than Beatrice reveal the meaning of grace (she leaves Heaven, in the poem, to come down into Limbo to alert Virgil and ask him to go awaken Dante who is in danger of eternal damnation). Virgil the Roman poet (his identity) is also an image of human reason, thus his place in Limbo; he is the best the human self can do on its own, as are all the other people in Limbo images of that aspect of the human self: reason, morality, goodness, virtue. In Dante's world and in orthodox Christian theology, only God, who came down from Heaven, can save the human self. Grace is God's gift of faith to the human soul, faith grounded in the one who came down from Heaven. Reason and virtue are real goods and necessary to the human self, but the best they can do in the end is make you proud and not humble.
The meaning of image requires a supernatural view of the cosmos, finally.