- rss output can have images. You can see example on e107.org: https://e107.org/xml/news/rss/
- to see how to do it - open e_rss.php in news plugin and find
$rss[$i]['media'] = $this->getMedia($value);
At the same file find fuction getMedia(). The News are specifics - they have one database field for multiple images separated by comma. If you have just single image, you doesn't need explode and foreach functionality.