The only change is to the section building the confirmation email at around line 1018
PHP Code:
      $this->products_ordered_html .=
      
'<tr>' "\n" .
      
//RB mod - Product Image            
      
'<td class="product-details" align="left" valign="top" width="30">' zen_get_products_image($this->products[$i]['id']) . '</td>' "\n" .
      
//RB mod - Product Image