Our detectives are back with the following intel on this WordPress site
The site is using the FAZ Blog Responsive Theme theme by Gaertner Datensysteme .
We could identify 4 plugins (there might be more) - auto-thickbox-plus , Better WordPress Google XML Sitemaps (support Sitemap Index, Multi-site and Google News) , NextCellent Gallery – NextGEN Legacy and Yoast SEO
A WordPress XML Sitemap plugin that comes with support for Sitemap Index, Multi-site and Google News sitemap. Image sitemap is supported, too.