you "hadn’t noticed"

[ackeiyword]

“Just in case you hadn’t noticed, there are other people on the airplane besides you. So don’t clip your toenails, snore with wild abandon, or do any type of personal business under a blanket!”

Question: Why the Past Participle tense is being used in this sentence?
Is it because it's an imaginary situation?
Thanks.

 

[Tdol]

It's an imaginary past situation (before the time of speaking), so it's in the past perfect.