Well... your page resides at
/detail/anything
which is correctly mapped to your merchant detail page...
Your images reside at
/detail/images/shop_no_logo_big.png
and similar, which is correctly mapped to your merchant detail page... The mount path doesn't know and doesn't care if it's a page request or a resource request. For all it is worth it could be the case that you're using the mount path to create the resource dynamically...
So the solution is to move your images to a location that doesn't match yout mount-path.