Somewhere in the last 24 hrs Google changed ( is testing ) the display of Review Summary Snippets in the knowledge panel.
Business Review Summary Snippets in Knowledge Panel
New Review Summary Display
Current Summary Display
Not Sure What Happened Here.
It looks like the reviews are now segmented into sections based upon terms contained within the review itself: Rooms, Service & facilities etc
These segmented sections then display an aggregated review summary for these determined sections.
The current parsed review snippets remain until there is a large enough data set of reviews to be able to display the new Summary Reviews by sections.
I have not noticed a change to other industries at the moment, it seems like Hotels is the test for this new look.
I have asked for an official statement, insight into the criteria required.