What Wittgenstein understood is that you can’t use words to explain representation, because words are representations themselves. It would be like trying to travel outside the Universe to show somebody what the Universe is – a feat that’s both impossible and unnecessary. A sentence shows what it means by its own sense. Thus, if I say ‘Jenny has an apple,’ I do not have to explain how the words ‘Jenny’ and ‘apple’ represent physical objects in the world; nor do I have to explain what ‘has’ means. We mutually understand that, if Jenny is right there and she has an orange in her hand, the proposition is false. It shows its sense. There is nothing more to say about it, as long as we both understand the rules of the language.