I've been seeing this everytime I go through that last cutscene, but I haven't yet looked into it:

This looks like how the door loading zones are loaded in, and I'm wondering if it is. It's probably not useful to any run, as the door probably doesn't open (similarly to how the Devlin 2 cutscene doors have no use yet still have loading zones) but I've been wondering for awhile where those loading zones might lead to if we could ever enter them.

Is that taken from my video ? I never noticed that. It does look like other loading zone black boxes that exist in the game. Strange. I know how to get out of bounds in this area however, I need to figure out where this black box is, and if it is reachable (because it seems quite far away and collision geo out of bounds is full of holes that you can't see)

EDIT: oh wait, this black box is on the side of the lighthouse. It might be because of the things that come out of the wall to push you. It might be spawned because of this. Imma test something

@Doodletones: there you go, that's what I suspected

EDIT: Out of bounds, in the middle of the void there is the TV floating to which you're teleported after being thrown out of the lighthouse. I explored this area in Redux (ManofSteel%) but I managed to get a glance of it on EOC, I know where it is, I just don't think I can reach it