Aaahh!!! Real Monsters Wiki
The Viewfinder discarded

The Viewfinder is a special chair which straps the user to it and on a projector, searches through their mind, and if it is found, displays footage of them scaring something. The Monsters most commonly use the viewfinder to show scares for their assignments.

Although the Viewfinder is most commonly used by the monsters, on rare occasions, it has also been used by humans. In The Switching Hour, Nicky (as Ickis) was grabbed by the arms of the chair and strapped onto it. The projector showed footage of Nicky accidentally scaring his cat on Halloween. Unlike the monsters, who scare humans as their jobs, Nicky wasn't intending to scare his cat; he only did it because Jake scared him with a Halloween prank.

Fraidy Cat

Footage of Nicky scaring his cat (accidentally).

The Viewfinder played a major role in A Room With No Viewfinder, in which Ickis accidentally releases it from the Lecture Hall (after Krumm gave him the idea to break it down), and so he, Krumm, and Oblina must go on a big journey to get it back before the Gromble notices. At one point, it ended up in a barber shop, in which a random person mistook it for a regular chair, but the device burned her head and hair slightly, so it was tossed outside.