What if you peeled a tangerine...
and looked at the shape:
What would you see?
We tried this and we saw all sorts of things:
It's amazing all the things that we saw the shape as: a crab, a ghost, a moose, an elephant. What can you see?
Here we see one thing as another thing. We might say it is that thing. This is called metaphor, especially when it's in writing. But we all experience metaphor in other places lots. Like when we have a toy. We play with this:
and even though it's made of wood and needs pushing we call it a train. Like with signs, one thing stands for another. The toy represents the train so well that we simply call it a train.