Most of the time I have seen the low quality posts in the review queues drop-down has a red dot left to it, probably indicating the queue is needed to be cleared urgently. But when I go to the review queue there's no post actually. But I have seen the same red dot near other queues as well, but rarely, and when I visit there's actually a considerable amount of posts.
Is this a bug or what's the explanation for this behavior?
UPDATE 1: Happened the same with Suggested Edits queue. Cleared the queue. Refreshed the page. Clicked on the Review queues icon. And this is how it looked.
UPDATE 2: Happened with Close votes queue as well