The proposition is a picture of reality.
The proposition is a model of the reality as we think it is.
4.011 At the first glance the proposition - say as it stands printed on paper - does not seem to be a picture of the reality of which it treats. But nor does the musical score appear at first sight to be a picture of a musical piece; nor does our phonetic spelling (letters) seem to be a picture of our spoken language.
And yet these symbolisms prove to be pictures - even in the ordinary sense of the word - of what they represent.
4.012 It is obvious that we perceive a proposition of the form "aRb" as a picture. Here the sign is obviously a likeness of the signified.
4.013 And if we penetrate to the essence of this pictorial nature we see that this is not disturbed by apparent irregularities (like the use of and in the score).
For these irregularities also picture what they are to express; only in another way.
4.014 (1) The gramophone record, the musical thought, the score, the waves of sound, all stand to one another in that pictorial internal relation, which holds between language and the world.
To all of them the logical structure is common.
(Like the two youths, their two horses and their lilies in the story. They are all in a certain sense one.)
4.015 The possibility of all similes, of all the images of our language, rests on the logic of representation.
4.016 In order to understand the essence of the proposition, consider hieroglyphic writing, which pictures the facts it describes.
And from it came the alphabet without the essence of the representation being lost.