Great Question! This is actually for your benefit! This gives you the chance to double-check the review before it goes live for others to see. In the case of a less-than-stellar review, this also gives you the opportunity to reach out to that customer and clear things up so they can remove or change it. 

The review will automatically go live after 7 days, or you can navigate to the review under the Reputation tab and release it from quarantine early.