MiniVend is a CGI program, and if you tried to use relative image paths you would end up with IMG tags like
<IMG SRC="/cgi-bin/simple/../whatever.jpg">
Not what you want. So MiniVend by default uses an
ImageDir for a prefix. In the demo that would be /simple/images/, so image specs that have no absolute path information are prefixed with
that.
In your MiniVend page, this tag
<IMG SRC="ordernow.gif">
will become
<IMG SRC="/simple/images/ordernow.gif">
and this:
<IMG SRC="items/00-0011.jpg">
will become
<IMG SRC="/simple/images/items/00-0011.jpg">
Absolute image paths are not affected, so if you reference an image at /other/images/whatever.gif, it will not be touched.