Have a look at the diagram below:

digram of interlocking squares

Now scroll down so that you can't see the diagram anymore. Without looking up again ...

You may now want to look at the diagram again. Do you notice things that you didn't see before?

Now look at this image:

Try the same thing: Now scroll down so that you can't see the diagram anymore.

Without looking up again ...

You may now want to look at the diagram again. Do you notice things that you didn't see before?