Woocommerce: Display order item thumbnails in transaction emails

edm-display-product-thumbnail-in-emails.php

<?php
/*
 * Enable order item thumbnail display in emails
 * Change order item thumbnail size
 * @see woocommerce/includes/wc-template-functions.php for hook
 */
function edm_display_product_thumbnail_in_emails( $args ) {
	
  /* Display image thumbnail in emails */
	$args['show_image'] = true;
	
  /* Edit image thumbnail size in px. Array( width, height )  */
	$args['image_size'] = array( 64, 64 );
	
	return $args;	
	
}
add_filter( 'woocommerce_email_order_items_args', 'edm_display_product_thumbnail_in_emails' );