I experienced once that someone asked me to reconsider my question before posting. I don't know "who" did that because I have a logical question to ask after I am sure about his.
No human sees them before posting.
I believe you're looking at the automated system that checks questions prior to answering: "Draft your question" followed by "Review your question". It points out errors such as:
- "Title is missing."
- "Please enter at least one tag; see a list of popular tags."
I don't think the precise algorithm has been made public, but no human is involved in this process. To my knowledge, diamond moderators don't have access to the results of this step. Diamond moderators go through the same process when asking questions.
In some instances the algorithm will outright block a question (e.g. if it has no tags). In other instances, the algorithm detects what it thinks are opinionated, argumentative, etc., which may be poorly received and so it gives a warning. It may or may not be correct.
I understand the motivation behind this feature is to assist new users in writing better questions, and thereby having an overall better user experience. (I'd speculate the underlying algorithm utilizes machine learning, and is trained using prior poorly received questions.)