"The Windows are creatures in the shape of a Window. The Window has a figure inside, always pointing at the target. If the target is unaware of the creature, it will attack immediately. "Windows" will generally appear on Level 1 through Level 2, although mainly on Level 1. Some Windows are safe when there is no shadowy figure behind them. Some can lead to "Level 1.5"."
Art done by me, credit to https://sketch.io/sketchpad/, the software I used to make this, and credit to http://backrooms-wiki.wikidot.com/ for the info. Use it if you want just give credit