modifying the recent posts shortcode

The following is the code for the shortcode for recent_posts –

[code]
add_shortcode('recent_posts', 'ns_recent_products');
function ns_recent_products( $atts ) {
global $woocommerce_loop;

$atts = shortcode_atts( array(
'per_page' => '12',
'columns' => '4',
'orderby' => 'date',
'order' => 'desc',
), $atts );

$meta_query = WC()->query->get_meta_query();

$args = array(
'post_type' => 'product',
'post_status' => 'publish',
'ignore_sticky_posts' => 1,
'posts_per_page' => $atts['per_page'],
'orderby' => $atts['orderby'],
'order' => $atts['order'],
'meta_query' => $meta_query
);

ob_start();

$products = new WP_Query( apply_filters( 'woocommerce_shortcode_products_query', $args, $atts ) );

$columns = absint( $atts['columns'] );
$woocommerce_loop['columns'] = $columns;

if ( $products->have_posts() ) : ?>

<?php woocommerce_product_loop_start(); ?>

<?php while ( $products->have_posts() ) : $products->the_post(); ?>

<?php wc_get_template_part( 'content', 'product' ); ?>

<?php endwhile; // end of the loop. ?>

<?php woocommerce_product_loop_end(); ?>

<?php endif;

wp_reset_postdata();

return '<div class="woocommerce columns-' . $columns . '">' . ob_get_clean() . '</div>';
}
[/code]

As a non-PHP developer, I don’t really understand how this code works (that much!) – the code outputs the image, title and button for each recent product. I’d like to modify it to include an extra variable (a custom attribute added in the Add Product page, let’s called it ‘Extra’) to be displayed below the title variable.

Any one can help?

Thanks.