HTML5 web app: How do I create a dynamic manifest file with drupal?
images should be attached to content via image field(if not I know another way, just ask), so you can create a new views and fetch only these images

add page display to that views and use it to create manifest, in this way you have dynamic manifest. if you want write it to file, small module is needed.

in this case you need have more than one manifest (multiple manifest), one of them is for your images

steps to create images manifest:


create views to fetch images: named manifest_1
create page display in that views: named page_1
create a small module to create your manifest, dirty sample:

function mymodule_menu() {
  return array(
      'manifest/images' => array(
          'page callback' => 'mymodule_manifest',
          'access arguments' => array('access content'),
          'type' => MENU_CALLBACK,
      )
  );
}

function mymodule_manifest() {
  $images = views_get_view_result('manifest_1', 'page_1');
  //sent header text/manifest
  //output image paths
  die();
}