Our detectives are back with the following intel on this WordPress site
The site is using the Sage Starter Theme V2 theme by Roots .
We could identify 2 plugins (there might be more) - ARVE Advanced Responsive Video Embedder (YouTube, Vimeo, HTML5 Video …) and Simple Social Icons
Easy responsive video embeds via URLs or shortcodes. Perfect drop-in replacement for WordPress' default embeds. Best plugin for videos?