Programmatically edit an image form field on a user account

Question

I have added an image field to user accounts using the "Manage Fields" user interface.

I am trying to make a form that users can use to change their picture.

Below is some code I have tried. In it, I explicitly set the URI of the image when I update the user account. However, for some reason, the URI of the account changes itself to "temporary://image_file_name". No image appears on the account page.

function profile_pic_edit_form($form, &$form_state) {
  $form['picture_upload'] = array(
    '#type' => 'file',
    '#title' => t('Upload picture'),
    '#size' => 48,
  );

  $form['submit'] = array(
    '#type' => 'submit',
    '#value' =>t('Change my picture'),
  );

  return $form;
}

function profile_pic_edit_form_submit($form, &$form_state) {
      $validators = array(
            'file_validate_is_image' => array(),
      );
      if ($file = file_save_upload('picture_upload', $validators)) {

      $file->status   = FILE_STATUS_PERMANENT;
      file_save_upload('picture_upload', $validators);

      $info = image_get_info($file->uri);
      $destination = 'public://pictures/profile_pics/'.$file->filename;
      if (file_copy($file, $destination, FILE_EXISTS_REPLACE)) {

        $pic_array = array(
             'fid' => $file->fid,
             'alt' => '',
             'title' => '',
             'width' => $info['width'],
             'height' => $info['height'],
             'uid' => $file->uid,
             'filename' => $file->filename,
             'uri' => $destination,
             'filemime' => $file->filemime,
             'filesize' => $file->filesize,
             'status' => '1',
             'timestamp' => $file->timestamp,
           );
      }
      else {
        form_set_error('picture_upload', t("Failed to upload the picture image."));
      }
      }
    $account = user_load(arg(1));  

    $edit = array(
     'field_profile_picture' => array(
       'und' => array(
         '0' => $form_state['values']['picture'],
          ),
        ),
     );
     user_save($account, $edit);
     //$account->field_profile_picture['und'][0]['uri']  is now  temporary://image_name.jpg
}