Why is the grey circle of the closing request in my account very frequent in REVIEW QUEUES compared to other items? Is there a specific reason or is it something random?
EDIT by comments:
A grey dot appears next to the review queue if there is something to review in that queue. This grey dot turns red if there is a sufficiently large number of reviews within that queue, denoting some urgency in reviewing that specific content. At that time, the actual review queue button also gets a red dot. Here is that view on Stack Overflow:
The Reopen Votes review queue (at that time) had a large number of reviews that needed addressing:
The review queues on TeX.SE is not that congested and therefore have the occasional grey dot, but rarely a red dot: