Batman: Arkham Knight Cool Forshadowing

[Boyobmas]

(Big Spoilers)

Spoiler

In the scene where Scarecrow makes Batman  watch Oracle commit a fear gas-induced suicide,
Joker can be seen nudging the gun she uses closer to her. This should be impossible as Joker is only a hallucination.

This is actually a subtle foreshowing to later in the game where it's revealed the entire scene was a hallucination.