The duck-rabbit, which appeared in Joseph Jastrow's Fact and Fable in Psychology (1900) is a drawing that can be seen in two distinct ways, as a duck (facing left) or as a rabbit (facing right.)

Approximately:



                                       _-"""-._
                                      '        `.
                                     /    @      \
                   c'"--...________.*             }
                    `-..____________             /
                     ......------"""             )
                    (__.....---"""""_           /
                                     `._       /
                                        )      \


The illusion is similar to the Necker cube, except that a pointy-out cube and a sticky-in cube are both cubes, whereas a duck is plainly not a rabbit. As with the cube, it's amusing to stare at the image and try and see both at once. The Necker cube and the duck-rabbit are both examples of what is properly called a bistable ambiguous image.

The duck-rabbit is used by philosopher Ludwig Wittgenstein in his Philosophical Investigations as an aid to an examination of what we mean by 'seeing as':

The change of aspect. "But surely you would say the picture is altogether different now!"

But what is different: my impression? my point of view? -- Can I say? I describe the alteration like a perception; quite as if the object had altered before my eyes.

[...]

If I saw the duck-rabbit as a rabbit, then I saw: these shapes and colours (I give them in detail) -- and I saw besides something like this: and here I point to a number of different pictures of rabbits. -- This shows the difference between the concepts.

'Seeing as ...' is not part of perception. And for that reason it is like seeing and again not like.

The example may perhaps also serve to illustrate the ubiquity of 'seeing as' - the ambiguity of the image renders the 'as' more noticeable, but, as Wittgenstein points out, when someone doesn't notice the ambiguity, seeing only a rabbit, for example, we who are aware of the ambiguity may quite correctly describe them as 'seeing it as a rabbit.'

This suggests to me that (almost) all seeing can be seen as 'seeing as' (when contrasted, say, with what's seen by a newborn baby.)

Reading, perhaps, is another case where 'seeing as' becomes noticeable; our experience of the text is quite different if we understand the language, or the analogy.