Does "outwardly projected" mean "outwardly projected (like a mirror)"?

Context:

Further than this, influenced by Platonic thought, Leonardo's conception of painting was, as an intellectual state or condition, outwardly projected. The painter who practised was before it. Although without a "manual act" painting could not be realized, its true problems-problems of light, of colour, pose and composition, of primitive and derivative shadow-had all to be grasped by the mind without bodily labour.

--- The Thoughts on Art and Life P10