At least one Stranger Things fan was baffled by the darkroom in Season 3

TIME

"What is the purpose of this ‘red room’ in Stranger Things?" one fan asked on StackExchange, expressing confusion for the concept of developing photos. “In Stranger Things, we frequently see Jonathan go inside this to ‘refine’ his photos or something. I don’t quite understand what happens here,” the user wrote. “He puts the photo in water, and somehow this makes it more clear? An example is in the first season when he refines Barbara’s photo and sees a little bit of the Demogorgon. Is this an old film technique, and if so, what is it called?” The post inspired jokes on Twitter about viewers feeling old. ALSO: Duffer Brothers break down Stranger Things' movie references.