501
here is my dirty hack for it 
open index.php
at the top after add
then open templates/extgallery_index.html
at the bottom look for line 52. it looks like this
change it to this
you should now see thumbs of each category
open index.php
at the top after
$xoopsTpl->assign('cats', $cats);
$photoHandler = xoops_getmodulehandler('publicphoto', 'extgallery');
for($i=0; $i <= count($cats); $i++){
$photos = $photoHandler->objectToArray($photoHandler->getAlbumPhotoPage($cats[$i]['cat_id'], 0, "photo_date", "DESC"),array('uid'));
}
$xoopsTpl->assign('photos', $photos);
then open templates/extgallery_index.html
at the bottom look for line 52. it looks like this
<h2><a title="<{$child.cat_name}>" href="<{xoAppUrl modules/extgallery/}>public-<{$display_type}>.php?id=<{$child.cat_id}>"><{$child.cat_name}></a></h2><br /><h3><{$child.cat_desc}></h3></td>
change it to this
<h2><a title="<{$child.cat_name}>" href="<{xoAppUrl modules/extgallery/}>public-<{$display_type}>.php?id=<{$child.cat_id}>">
<{$child.cat_name}></a>
</h2>
<br />
<h3><{$child.cat_desc}></h3>
<{foreach item=photo from=$photos}>
<{if $photo.cat_id == $child.cat_id}>
<img src="<{xoAppUrl}>uploads/extgallery/public-photo/thumb/thumb_<{$photo.photo_name}>" />
<{/if}>
<{/foreach}>
</td>
you should now see thumbs of each category
