The tips in the review screen advise to "look for hidden gems". What are hidden gems and what is a reviewer supposed to do if one is found?
Hard to define, but hopefully you'd know one if you saw it.
Imagine a spectacular multi-page essay by a first-time user in the new review queue. Say Hello! Tweet and Twitter!
This can also happen in other queues, in different ways. Imagine in the low-quality queue, a succinct pithy witticism that strikes to the very heart of the matter with such fiendish aplomb and keen relentless artistry doesn't even need a full paragraph to ... uh... say whatever OP needed to hear or something, i dunno.
Imagine in the close queue, a noob first post with a basic textbook mistake. Close, right? But what if there's thoughtful answer that carefully addresses the full complexity of the issue from the basic parts the noob can understand. Sometimes a good answer saves a bad question. Maybe you just fix some grammar and remove <blink> and stuff.
The point is to keep your brain on when reviewing. If you zone out and don't really have an opinion, don't start clicking on auto-pilot. Go watch some tv, or take a nap or something.
The badges aren't going anywhere.