Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Q&A for work
Connect and share knowledge within a single location that is structured and easy to search.
Why Ask Ubuntu tested me while reviewing close votes?What was the purpose of this kind of tests?
This would explain most of your doubts but in summary is a test if you are paying attention (and doing a good job) to the review queue.