Add CSS or other content to the output of the Stock Exporter for WooCommerce plugin when "HTML table on new window" is chosen

wse_screen_new_header.php

<?php

add_action( 'wse_screen_new_header', 'wse_screen_new_header_css', 11 );
function wse_screen_new_header_css() {
	?>
	<style type="text/css">
		#stock-export-table .column-value-image img {
			max-width: 200px;
			max-height: 200px;
		}
	</style>
	<?php
}

add_action( 'wse_screen_new_footer', 'wse_screen_new_footer_notes', 9 );
function wse_screen_new_footer_notes() {
	?>
	<p>Some footer notes</p>
	<?php
}