Questions about "shared" layout -- how do you generate one?

About a month ago, u/VanDeGraph posted this thread, highlighting the "shared" layout:

https://www.reddit.com/r/youtube/comments/54hc0t/youtube_has_a_new_shared_layout_for_videos/

Does anybody know how to generate a URL like this? I tried Google+ and manual URL manipulation. Also, how long has this been around and is there an official name for it?