Replace taxonomy term reference options with images in Drupal

sh_member_signup.module

/**
 * Implements hook_form_FORM_ID_alter() for premium_plus_order_entityform_edit_form().
 *
 * Replace the options with images from the taxonomy term
 */
function sh_member_signup_form_premium_plus_order_entityform_edit_form_alter(&$form, &$form_state, $form_id) {
  foreach ($form as $formitem_name => $formitem) {
    if (isset($formitem['#attributes']['class']) && in_array('field-type-taxonomy-term-reference', $formitem['#attributes']['class'])) {
      foreach ($formitem['und']['#options'] as $tid => $option) {
        $term = taxonomy_term_load($tid);
        $image_display = field_view_field('taxonomy_term', $term, 'field_premplus_image', 'default');

        $form[$formitem_name]['und']['#options'][$tid] = $option . drupal_render($image_display);
      }
    }
  }
}