I can't access backend of your site with provided info, if you want to place the image on top of this article detailed page, you can edit this file:
and move this snippet of code (which renders the full text image) to the place you wish:
<?php echo LayoutHelper::render('joomla.content.full_image', $this->item); ?>
here is a sample I changed:
May I know where this image comes from? image of category?