These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Alternative Character Interpretation: The director stated that the end of the movie, showing a photograph of the Yorkin Family with Sy beaming among them was meant to be ambiguous. He said that in his opinion, the Yorkins forgave Sy because he ended up saving their family, and he got to be part of them like he always wanted to. But taking the work by itself, it's equally plausible that we are seeing Sy is still trapped in his delusions, thinking that he's part of their family unit.
Fridge Brilliance: Sy's nightmare comes across as a BLAM, until he is chased by the police and runs across a hall where a lecture about a treatment for retinal degeneration is held. The former symbolises Sy's increasing delusional state and aggression, the latter symbolises realising the mistakes he's made.
Fridge Horror: Some of Sy's earlier lines become a lot creepier after watching the interrogation scene. For example, when he casually mentions to Jake how he was sick a lot as a child. Specifically mono... And hepatitis.