{{ImageLink/doc}}} places a link on the top of pages to the image category associated with the subject of that page. It's related to {{ImageLink}}, but works for people and things. It assumes that the category to which you want to link will have the same name as the page you're putting it on.
For instance, on the page Fourth Doctor, you can just place {{ImageLink/doc}}.
However, because the title for the category associated with images of Susan Campbell is actually Susan images, you'd need to specify all the words that come before "images" in the category name.
Thus, on the page Susan Campbell, you'd need to type {{ImageLink/doc|Susan}}.