Full Idea
David's painting of Napoleon (on a white horse) is a 'picture' of Napoleon, and a 'symbol' of leadership, courage, adventure. It manages to be about something concrete and something abstract.
Gist of Idea
David's 'Napoleon' is about something concrete and something abstract
Source
James Robert Brown (Philosophy of Mathematics [1999], Ch. 3)
Book Reference
Brown,James Robert: 'Philosophy of Mathematics' [Routledge 2002], p.40
A Reaction
This strikes me as the germ of an extremely important idea - that abstraction is involved in our perception of the concrete, so that they are not two entirely separate realms. Seeing 'as' involves abstraction.