The names Tim and Alan Russell were used in this short, as well as the actual Oculus movie? I don't think they are supposed to be the same characters... Did they really just not want to think of different names or something?
"1000 Voices Screaming, If Hell Exists...This Is It"
My guess is that this is on tim after the events of "chapter 1" (aka the motion picture movie Oculus). This short is what the movie was based on. The fact that it's titled Chapter 3 (for the short) implies this will come into play after a sequel to the longer movie (when Tim gets out of lock up for the second time(after the events that occurred with his sisters death). But that's just guess work from me, but it's how I made sense of it.
Long story short... This short video was the original and the reason that the longer version was made. It came from this short idea. Or so I've read.