If you search for a keyword phrase that triggers local listings in Google’s Web search results, such as searching for [barber], Google will show you Google Business listings. If you click on the reviews on one of those listings, instead of taking you to the Google Business Local page, Google will pop open a dynamic overlay window on top of the web search results and show you those reviews for those listings.
Here is a screen shot I took on my Macbook using Chrome while signed in:
Then click on the reviews link and the overlay shows up, rather than a new page being loaded:
We’ve emailed Google for a comment and have yet to hear back.
A hat tip goes to Andrew Shotland for spotting this first.