It probably is a learning system... It got trained more. The review itself doesn't have to change. The system merely adjusted its parameters due to more exposure to new reviews.
Anyone who uses this site really needs to do a re-analysis, because on the products I just tested I'd rate its prior ability to detect fakes (reviews and reviewers) at F.
After re-analysis I'll upgrade its ability to C.
TBH, I don't understand the point. I trust my own ability to evaluate reviews more than the unknown logic of a third party website, which may have its own interests/motives influencing its reviews of reviews.