Google seems to be rolling out review snippets to the local 3-pack and the local finder.
Google began testing the review snippets almost 2 years ago, and I am now able to replicate it on different devices and in different browsers which usually a strong indicator of a rollout.
Google tries to pull reviews that are relevant to user’s query, although, the retrieval algorithm does not seem to always understand the semantics of reviews as we can see from this example:
The new review snippet is often displayed next to the “website mention” feature in the local finder (when both are available) . “Their website mentions” was rolled out in September 2017 to mobile search results, but is still not available on desktop.
When it comes to local 3-packs in mobile search the “website mention” feature is prioritized over the new review snippet, and only the former is displayed even when both of the features are available.
However, Google seems to be testing dropping the Website Mention feature altogether, which I think makes some sense, as the local finder can get a little too noisy with all these snippets:
This rollout is another proof (if you needed one) of the importance of reviews in Local Search.