Image files (such as GIF Graphic Information Files) are used in many web pages.
Some World Wide Web browsers (like Netscape or Explorer) are capable of displaying these types of files on your terminal, without going to the trouble of downloading. Since LYNX is a text-only browser, you can't usually see these images.
However... pressing * while viewing a document will change all inline images into links so that you can download and view them offline on your local machine with a graphics viewer.
There are a number of good shareware and freeware viewers available.