Search for a product on Google and you might see a Knowledge Graph card to the right of the result links containing details on the product as well as links to sites selling it and the full Google Shopping reviews page. You may now also see snippets of what people are saying regarding certain aspects of a product.
First spotted by Search Engine Land, Google seems to be pulling quotes from the product reviews that it aggregates from other websites and placing them inside Search product cards. The company gets most of these reviews from the product pages of websites selling the item – Rakuten.com Shopping and B&H Photo are two places the reviews for the above speakers come from, for example.
As Search Engine Land notes, you can click through to see all the reviews for a product, but on the full reviews page the only link provided against each review simply goes to the product page hosting the review – it doesn’t take you to that exact review on the host site.
Google is constantly adjusting its Knowledge Graph cards, most recently removing Google+ posts from the cards for popular businesses.