Over the past week or two, I've been getting daily reports from people that going to Google and searching for something on your smartphone now shows the people also search for carousel under some snippets.
Yes, the behavior is that you go to Google, search for something, click on a result. Then if you click back, under the snippet of the result you clicked on, you get this carousel for "people also search for..."
So in this example below, I clicked on EarthLink, then went to the site, clicked the back button on the browser and the people also search for box came up:
This behavior is live in all of my mobile browser tests.
Forum discussion at Twitter.