FWIW, the -4 negative reputation points for the 2 downvotes (which were cast before the upvotes) were exceptionally not counted because that would have resulted in a total non-positive reputation for the user.
The counter "Your daily reviews X/20" just means that you can do a maximum of 20 reviews per day per queue, not that there are actually 20 items in the queue for you to review.
"The queue has been cleared", on the other hand, just means that the queue is empty for you, i.e. there are no more items you are currently eligible to review.
Your question has been upvoted twice and downvoted twice. The "net votes" on the post is thus 0, making it look like there is no vote at all. Users with the Established User Privilege (1000 reputation) can view vote counts.
So, you gained 20 reputation by 2 upvotes on your post but these were not visible to you because there were also 2 downvotes. ...