- When arguing about what to do, one of the characters responds to a suggestion that they all just stay in the house as unrealistic and unhelpful. When Em finally finds a "happy" reality, everyone has actually just stayed inside. Turns out that was a pretty good solution.
- Earlier in the movie, Mike mentions being in "Roswell" for four seasons. Laurie says she's a fan, asks him which episode. Mike says he was in every episode, but Laurie can't remember him. This is a very early sign of the comet's effect.
- The movie only shows us how the people in one house handled the comet's passing but there is no reason to believe they were the only ones affected. There are presumably many other houses on that street that were directly beneath it and probably several adjacent streets that are equally as populated, since it doesn't appear to be a rural area. Once you multiply that population across the different realities it suddenly becomes very likely that countless thousands of lives were changed by the event, mostly for the worse.
- How does the comet's influence "know" what a house is and where the property ends? Is the effect a cylinder that just happened to be centered upon the house in that one instance? Are there other instances with less clean borders? What happens when a house is split by two different zones with people on either side, would they just vanish from each other's view with the dark space cutting through the building? Are there patches of forest with terrified deer staring out into the infinite blackness suddenly surrounding them? Why does the space between the parallel houses resemble a street? Obviously the answer to all of these is "because it's a movie" but in-universe it's certainly very difficult to figure out what the rules might be.
- Not quite "fridge" since it's immediately quite obvious that things are about to get bad for Emily, but imagining what might happen to her in the new universe leads to some very horrifying possibilities. She's probably about to be arrested for attempted murder so the real question is whether or not anyone believes she's from another reality. If they don't, she's going to prison and if she ever gets out she'll be homeless without anything to her name. If they do, the government is probably going to want to study her and as a violent criminal not very many people are going to be rushing to stop them from locking her away forever for whatever tests they want to conduct.
Fridge / Coherence