Get attachment images does not return any attached images

Question

According to WP codex the code copied below will return a list of images attached to a "page". I have yet see this happen and I'm at a complete loss as to why:

I have created a template page called gallery-test and within it I have pasted the code as in the example listed in the WP codex,

...I have set my page to the gallery-test template page. I have attached 5 images with titles to the page,

... the result is an empty page.

Any suggestions or help would be most appreciated!

 <ul>
    <?php if ( have_posts() ) : while ( have_posts() ) : the_post();    

     $args = array(
       'post_type' => 'attachment',
       'numberposts' => -1,
       'post_status' => null,
       'post_parent' => $post->ID
      );

      $attachments = get_posts( $args );
         if ( $attachments ) {
            foreach ( $attachments as $attachment ) {
               echo '<li>';
               echo wp_get_attachment_image( $attachment->ID, 'full' );
               echo '<p>';
               echo apply_filters( 'the_title', $attachment->post_title );
               echo '</p></li>';
              }
         }

     endwhile; endif; ?>
    </ul>

Answer 1

For this feature to work the images must be uploaded to the media library from that page. In other words, clicking the "Add Media" button and adding images already in your media library won't do it. You must click "Add Media" then "Upload Images" and add them to the page.