In addition to telling readers why an illustration is important, why else should you refer to it in the text of your document?

To assist the readers to relate objects and actions with texts.

Explanation:

Aside from telling readers why an illustration is important, the other reason you should refer to it in the text of your document is "to assist the readers to relate objects and actions with texts."

This is evident in the fact that illustration in a text is a means of presenting a graphical representation of ideas, processes, or theories to aid or give elaborate meaning to what is written.

answer; ///they are able to see how many people have read or watched some part of a commercial;