2.12 A picture is a model of reality.


2.13 In a picture objects have the elements of the picture corresponding to
them.


2.131 In a picture the elements of the picture are the representatives of
objects.


2.14 What constitutes a picture is that its elements are related to one
another in a determinate way.


2.141 A picture is a fact.


2.15 The fact that the elements of a picture are related to one another in
a determinate way represents that things are related to one another in the
same way. Let us call this connexion of its elements the structure of the
picture, and let us call the possibility of this structure the pictorial
form of the picture.


2.151 Pictorial form is the possibility that things are related to one
another in the same way as the elements of the picture.