The distinction of image and likeness has been a common one in the history of theology, East and West, and in the West at least it overlaps with the nature/grace dualism.  Image for Bonventure “denotes a kind of ‘shape,’ that is, a quantitative feature of quality or a qualitative feature of quantity; but a likeness attributes the same quality to different things.”  Image is “agreement in quantity” while likeness is “sharing in quality.”  Image is “something in a natural order” but likeness is “in the order of grace.”  Image imitates its model; likeness participates in the archetype.

Not for Thomas:

He acknowledges there are two kinds of similitudo , one “by participation in the same quality” and the other “by means of a certain proportion.”  Two hot things are like in the first sense, God and the sun in the second sense.  The most telling representations and likeness are those that have “a sharing of form, as sight is like to colour, than that which is by analogy, as sight is to intellect, which may be compared as having similar relations to their objects.  So the mind has a more expressior similitudo to the Trinity in its knowing than it has in knowing itself.”

This sounds like the same image/likeness dualism, but for Thomas this is a matter of degree.  As Denys Turner explains, “every image to some degree participates in what it images . . . like Hugh and Bonaventure, [Thomas] holds there is a distinction to be made between those images which participate more and those which participate less in what they image.”  But they differ because “Thomas would say: the more participative a representation, the greater its degree of likeness, and so the greater its power as image.  Bonaventure, by contrast, would say: the more participative the representation the more it is likeness rather than image.”

In short: Further evidence that de Lubac got Thomas right.