For many of you, film photography probably already seems a distant memory, so I think I’d better explain what’s going on here. When you work with film, you need to “process” or “develop” it in a darkroom. This is a process involving several chemicals which change the film so that it can be exposed to light without harm. Here Raven is depicted in the final steps of the process. He has finished all the chemical baths and removed the film from the developing tank. He will not ruin the film at this point because it is no longer sensitive to light. This probably sounds absurdly old fashioned, but believe it or not, this is how it used to work, and still does in many places (I’ve done it many times).
Also: Who’s that in the last two panels? You’ll find out later.