Correct me if I'm wrong here, but truth is something that arises out of the relationship between language and the world. If I look at a picture alone, it tells me nothing. In the previous incarnation of this lecture, I was going to put a picture of the Titanic and the Lusitania up on the screen. They look very, very similar - four smokestacks. They look almost identical. You look at either picture, true or false? Neither. Put a caption at the bottom of one of them, that changes everything. If you put in the caption, 'This is the Lusitania,' and the picture is a picture of the Lusitania, then the caption is true. However, the picture itself is neither true nor false. It's just a picture.