2.1 We make pictures of facts for ourselves.

This is the translation that Black (p. 76) calls the literal one.

Cf. Heinrich Hertz The Principles of Mechanics (New York: Dover Publications, 1956) p. 1: “We form for ourselves pictures or symbols of external objects…” Hertz is concerned with the question how scientists can represent nature in such a way as to allow for making predictions.

Here, apparently, is the start of the famous picture theory, which seems to be beginning on a very shaky foundation given my previous comment.

Schopenhauer on pictures, language, etc. says that language does not communicate perceptions or anything that needs to be translated into pictures in the imagination, at least not usually. Language deals with abstract conceptions, which is why animals cannot understand it even though they perceive as we do. Images can never do justice to the concepts they occasionally represent. “Now, although concepts are fundamentally different from ideas of perception, they stand in a necessary relation to them, without which they would be nothing. This relation therefore constitutes the whole nature and existence of concepts. Reflection is necessarily a copy, a repetition, of the original world of perception, albeit a special kind of copy in an entirely different material. Thus concepts may quite properly be called ideas of ideas.” (Everyman edition of Schopenhauer’s WWR, pp. 10-11.)

“[T]rue philosophy must always be idealistic; indeed, it must be so in order to be merely honest." (Ibid., p. 13) “To the empirical standpoint of the other sciences it is quite appropriate to assume the objective world as something absolutely given; but it is not appropriate to the standpoint of philosophy, which by its nature has to go back to what is first and original. Only consciousness is immediately given; therefore, the basis of philosophy is limited to facts of consciousness, i.e., it is essentially idealistic.” (Ibid.)

What is available to our immediate consciousness “is limited by our skin, or rather by the very tips of the nerves which emanate from the cerebral system. Beyond this lies a world of which we have no knowledge except through pictures in our head.” (Ibid., p. 17) According to Schopenhauer, thinking is a kind of reflection of the empirical world, but because it deals with abstract concepts, it is perhaps better compared with algebra. See Gardiner p. 111, and Schopenhauer’s Erslingsmanuskripte §34.