It does what it is supposed to do. My plans were to simply have an image show for a particular category, and this was easily achieved by naming image files according to the category ID. It seems even more useful than I planned, being able to assign images to authors, sections, articles, etc. as well.

One suggestion to the author. I found a problem where the option for "Use default file option=no" doesn't work properly, and tries to show the default image anyway. Adding the following to line 334 of mhi_classes.inc (should be the first line in the switch on $mode case for 'default' in selectContextImage), and an end-if bracket at the end of the case, will fix the issue:

if ( $this->params->Default->Use!='0' ) {

}