Google "Show more results..." plus box on search results

Now when you search Google, on some search results, Google is showing a “plus icon” reading to “Show more results from www...”. Clicking it expands further results from the same domain dynamically, right on the page.   

Now when you search Google, on some search results, Google is showing a “plus icon” reading to “Show more results from www...”. Clicking it expands further results from the same domain dynamically, right on the page.