How to modify display of image form metadata after upload on node edit form?
Here's the answer, which I discovered after some further research:

/**
 * Implements hook_field_widget_form_alter().
 */
function MYMODULE_field_widget_form_alter(&amp;$element, &amp;$form_state, $context) {
  // If this is an an image on a slideshow
  if (isset($context['form']['type']['#value']) &amp;&amp; $context['form']['type']['#value'] == 'slideshow') {
    // Loop through the element children (there will always be at least one).
    foreach (element_children($element) as $key =&gt; $child) {
      // Add the new process function to the element
      $element[$key]['#process'][] = '_MYMODULE_image_field_widget_process';
    }
  }
}

function _MYMODULE_image_field_widget_process($element, &amp;$form_state, $form) {
  // Change the way metadata form fields are displayed;
  unset($element['title']['#description']);
  unset($element['alt']['#description']);
  $element['title']['#weight'] = '-4';
  $element['alt']['#title'] = 'Description';
  // Return the altered element
  return $element;
}