Images? No, there aren’t any images. The icons are created with Font Awesome. You can just change the class name to the icon you want. If you would rather use images you can of course insert an image tag in there instead.
Here’s a reference for Font Awesome icons: http://fortawesome.github.io/Font-Awesome/icons/
I didn’t understand the second question about “you put what in the ” ? ” the link to the corresponding page?” If you can clarify that for me I’m sure I can answer it.