rss feed image

// add featured image to rss feed
add_filter( 'the_content', 'ld_featured_image_in_feed' );
function ld_featured_image_in_feed( $content ) {
    global $post;
    if( is_feed() ) {
        if ( has_post_thumbnail( $post->ID ) ){
            $feat_image_output = get_the_post_thumbnail( $post->ID, 'full', array( 'style' => 'height: auto;margin-bottom:2em;max-width: 600px !important;padding-top: 0.75em;width: 100% !important;' ) );
            $content = $feat_image_output . $content;
        }
    }
    return $content;
}