If all reviews are approved, even low quality reviews are available to be seen, and how about spam? What if a user is proven to be writing spam reviews to make the results of a product appear better or worse?
I agree on that all reviews should all be seen whether it is a quality review or not. That makes Lina being transparent.
I think it's better if all reviews are approved, then in case a review seems to be spam or not credible, there should just be a report to mod button like bct or mark as spam like in fb. Reported reviews should still be available to be seen but not included in the score.
There is also "like/agree" button on each review (that's how I understand it) so that a review with lots of likes will be the one that looks credible. And that's how common users will be promoted to Helper if he has published lots of quality reviews with lots of likes.