<th class="product-thumb"><?php _e( 'Image', 'woocommerce' ); ?></th>

<td class="product-thumb">
    <?php $thumb = get_the_post_thumbnail_url($item['product_id'], 'shop_catalog'); ?>
    <?php
        if(!empty($thumb)) {
           echo "<img src='{$thumb}'/>";
        }
    ?>
</td>