Her interior dialogue/monologue defines Snow. It’s that old theatrical turnip: you can’t ‘play’ a king, you need everybody else on stage saying to each other, and therefore to the audience, stuff like “There goes the King, isn’t he a piece of work, how evil, how lovely, how benevolent, how cruel, how brilliant he is!” The idea of him, the definition of him, the audience’s perception of him, is primarily instilled by the observations of others and once that idea is set, the audience’s view of the character is pretty much unyielding. And in Snow’s case, that definition, of course, comes from Katniss.
Soooo Donald Sutherland just proved he knows President Snow scary-well, in this letter he wrote Gary Ross right before The Hunger Games started filming last year. I used to think Christoph Waltz was the best guy for the role, but this is pretty damn impressive.