It looks like Google is showing titles on some of the featured snippets results on mobile. Mordy Oberstein from RankRanger posted on Twitter that he spotted it and shared some screen shots. I was only able to replicate it on mobile for the query [how to find gold] and here it is:
Here are the screen shots showing titles at the top of the Google featured snippets from Mordy:
— Mordy Oberstein (@MordyOberstein) April 23, 2018
Forum discussion at Twitter.