Google seems to be testing a new reviews stars format and user interface on mobile devices. The new format places the reviews summary below the snippet, as opposed to in the middle of the snippet.

Here is a screen shot of the normal reviews snippet in the search results:

Now, @NortheasternExt posted on Twitter the new test, which places the reviews summary under the snippet, which essentially takes up more snippet space.

I personally cannot replicate this new user interface, it is a small change but adds a bunch more vertical pixels to the scroll on mobile.

Forum discussion at Twitter.