This level censors itself from photographs. Rodrick entered this room. The room had blank white walls, a table, a chair, a locked door, and a bunch of papers. One paper had something on it. This helped Rodrick imagine a key, so he can use it to unlock the door. He was then led to a greenish walled room, with a Warp Pipe. There was another paper for instructions. Rodrick dropped the key into it, and then escaped/pressed on. Illuminati watched him pass his tests.
"If you're reading this, you're the first to enter Level 12. You're in a pretty blank room, no key, and a locked door to your way out. So how will you get the key? Considering the Backrooms is basically a separate place from reality, it should be easy to answer. This is your test, I'm hoping you escape. I know who you are, and I'm watching. If you never manage to escape, you will stay forever locked away. Just in case you do get locked away, there's some blank papers to make you panic about the pitch white around the room."
"If you made it here, I expected you imagined a key. Good job, you cheated the system. Now drop that key into that Warp Pipe."