The four pics you are referring to are only for having Ace as the main character. Pairing other characters will not get you these pics yet.
You have to play as Ace, like we said. <3 You would have to do a run, as Ace, picking all 4 different friends night 1, and then get to the night the scene in question occurs.
There will be different combos of chars and methods in the future, but right now, only Ace as a main character has access to these.