A person who is not a supervisor or management of any kind who snoops in an effort to gain information, to go back and tell the real supervisor in an effort to be promoted.
"Jacob came back from his break 20 minutes late." Lisa tells her manager.
A person in a position of self-appointed authority, without concrete skills or no-how, who provides unsolicited and obnoxious advice, management and oversight.
Snoopervising includes breaking into personal email; searching computer use history; reviewing phone logs, SMS and MMS; checking car mileage in relation to stated travel plans; and other investigative actions.
Sneakingly supervising a project. Involves spying and other sleuth techniques because you don't have direct supervision powers but want the job done well.
To your roommate: "Don't let my parents into my room without your snoopervision. I didn't get a chance to hide my diary very well, so an un-snooper-vised visit could be disastrous"