$attachment_title = get_the_title($thumbnail_id);
	$alt_text = get_post_meta($thumbnail_id, '_wp_attachment_image_alt', true);

	$image_output = sprintf(
		'<img src="%1$s" title="%6$s" alt="%2$s"%3$s %4$s/>%5$s',
		esc_attr( $thumb_src ),
		esc_attr( $alt_text ),
		( !empty( $args['img_class'] ) ? sprintf( ' class="%s"', esc_attr( implode( ' ', $args['img_class'] ) ) ) : '' ),
		( !empty( $img_style ) ? sprintf( ' style="%s"', esc_attr( $img_style ) ) : '' ),
		$args['img_after'],
		$alt_text
	);