The function related images gives you now the possibilities to append images to a post (not a page) which contain related tags or categories. You can activate this in the options or you can modify your theme files, to place the images at a different position.
This is the code for the theme files :
the_related_images([string $type],[int $numbers]);
Possibles values for $type are:
- tags (add related images based on the tags)
- category (add related images based on the selected categories)
$numbers : Maximal number of images to show