From "Ludwig Wittgenstein’s passion for looking, not thinking" by Ray Monk in the New Statesman on 25 August 2013.
"Thus, at the heart of Wittgenstein’s philosophy is what he calls “the understanding which consists in ‘seeing connections’ ”. Here “seeing” is meant not metaphorically, but literally. That is why, towards the end of the book, he devotes so much space to a discussion of the phenomenon of seeing ambiguous figures such as the duck-rabbit. When we “change the aspect” under which we look at the picture, seeing it now as a duck, now as a rabbit, what changes? Not the picture, for that stays the same. What changes is not any object but rather the way we look at it; we see it differently, just as we see a face differently when we look at it, first as an expression of happiness and then as an expression of pride."