Woocommerce 3.1 Add product image to order confirmation email not working

I’m using the following code in my theme functions.php to add product images in order email. But the image is not showing in the email. Did I miss anything? I’m using WooCommerce 3.1

function sww_add_images_woocommerce_emails( $output, $order ) {

    // set a flag so we don't recursively call this filter
    static $run = 0;

    // if we've already run this filter, bail out
    if ( $run ) {
        return $output;
    }

    $args = array(
        'show_sku'      => false,
        'show_image'    => true,
        'image_size'    => array( 100, 100 ),
    );

    // increment our flag so we don't run again
    $run++;

    // if first run, give WooComm our updated table
    return $order->email_order_items_table( $args );
}
add_filter( 'woocommerce_email_order_items_table', 'sww_add_images_woocommerce_emails', 10, 2 ); 

Try this code in functions.php inside your theme folder.

add_filter( 'woocommerce_email_order_items_args', 'iconic_email_order_items_args', 10, 1 );

function iconic_email_order_items_args( $args ) {

    $args['show_image'] = true;

    return $args;

}