3 A logical picture of facts is a thought.
So, what has so far been called a picture is now being called a logical picture, making clearer its non-physical (and non-metaphysical) nature. It is now called a thought, which is surely a Fregean idea, being more to do with propositions than anything psychological. But it may be premature to assume that Wittgenstein is thinking in such a Fregean way here.
Black (p. 96): “I think W. deviates from Frege in regarding a ‘thought’ as the propositional sign in use, i.e. as the sentence with its sense, i.e. as the significant proposition. The ‘thought’ is not, as with Frege, the ideal sense of the proposition.” Black also quotes Ramsey (Foundations, p. 274): “As to the relation between a proposition and a thought Mr W. is rather obscure…”