Google has long offered related searches at the bottom of search results, but this is a bit different. The above widget, which now appears for some users when you tap on a search result and then go back, shows relevant searches to whatever page you tapped on.
As opposed to the related search results at the bottom of each results page, this appears directly under whatever link you picked. Considering the vast amount of searches I do on my phone don't require me to scroll all the way down to the bottom, it makes sense to add recommendations directly into results. Additionally, the results seem to be tailored to the link itself, as opposed to being based on your query.
This seems to only be available to the mobile Google site and the Google app, not the desktop site.