add_action( 'wp_enqueue_scripts', 'mini_enqueue_scripts' );

add_filter( 'manage_shop_order_posts_columns', 'woocommerce_add_order_notes_column', 99 );
function woocommerce_add_order_notes_column( $columns ) {
    $columns['order_notes'] = __('Customer note', 'woocommerce');
    return $columns;
}

add_action( 'manage_shop_order_posts_custom_column' , 'woocommerce_show_order_notes_column', 10, 2 );
function woocommerce_show_order_notes_column( $column_name, $order_id ) {
    switch ( $column_name ) {
        case 'order_notes':
            $order = wc_get_order( $order_id );
            $note = $order->get_customer_note();
            if ( !empty($note) ) {
                echo '<span class="note-on tips" data-tip="' . wc_sanitize_tooltip( $note ) . '">' . __( 'Yes', 'woocommerce' ) . '</span>';
            } else {
                echo '<span class="na">&ndash;</span>';
            }
            break;
    }
}