How to display image inside a form
$form['y']['image_div'] = array(
  '#prefix' =&gt; '&lt;div class="image"&gt;',
  '#suffix' =&gt; '&lt;/div&gt;',
  '#markup' =&gt; theme('image', array(
    'path' =&gt; 'https://4.bp.blogspot.com/-tGbw82Gz8hA/WPR6WiOGPaI/AAAAAAAAEjk/JDPdpK3p-8wAUe2QTQbtWSdTZR_DBc-QACLcB/s640/Checkout.png',
  )),
);


And in your template file:

print drupal_render($form['y']['image_div']);


Result: