How to get the URL addresses of all the photos on form
I implemented it this way. Hopefully this will save someone's time. The code works well if you upload files, delete if it works after the removal of the second file in this list and removes only the first remote URL.

function testmodule_form_page_node_form_alter(&amp;$form, &amp;$form_state, $form_id) {
    $form['field_photo']['#element_validate'][] = 'my_function';
}

function my_function($element, &amp;$form, &amp;$form_state){

        $lang = $element['#language'];
        foreach (element_children($element[$lang]) as $key) {
                $fid = $element[$lang][$key]['#value']['fid'];
                $file = file_load($fid);
                $url = file_create_url($file-&gt;uri);
                dpm($url);
        }
}