The Feedback section shows the negative comments, displayed only internally, that would have otherwise appeared on a public review site.
When reviewers receive an email (1) or SMS/text message they click a link that leads to a website where they rate their experience (2). If they click on a frown or indifferent face they are directed to an internal form where they leave their comments (3). Those internal comments show up here (4) instead of public review sites. This is the “user segmentation” configured on the Get Reviews page.