Here is a new test Google is running, where when you do a search on mobile, scroll down and then scroll back up, Google will show you other search refinement options for your original query. I cannot replicate this but Brodie Clark posted a video of this in action on Twitter.
Here is a screen shot:
This is what I see, a static box asking you to refine your search results, but it is there immediately, with or without scroll, it is there:
Here is a GIF of part of this in action from Brodie:
Brodie said “This is pretty cool. A tidy looking sticky search bar test on mobile. Has related queries at the top & a switch from the magnifying glass to the G logo.”
Forum discussion at Twitter.