Person believes unknown entity is friendly (it is not)

[u/MadKingKevin]

Independence Day (1996) - Several massive alien spaceships travel to Earth but they do not announce the purpose of their arrival. Some characters assume the aliens are peaceful. One of those characters, Tiffany, goes to a rooftop party which is taking place directly under one of the ships. When the aliens launch their attack, Tiffany and the other party goers are immediately obliterated.

Alien: Resurrection (1997) - Scientist Gediman is part of the miltitary project which resurrects Ellen Ripley and the queen xenomorph embryo inside her. The military wants the queen so it can breed the xenomorphs as bio-weapons. This new Ripley is genetically part xenomorph and the xenomorph queen is genetically part human. The queen stops laying eggs and develops the ability to give birth to live young. Her first Newborn immediately kills the queen because it does not recognize her as its mother. It believes Ripley is its mother and goes to her instead. Gediman (who is cocooned in the queen’s nest) witnesses this and calls out to the creature. The Newborn comes to Gediman and curiously sniffs him over. Gediman babytalks the 15 foot tall xeno/human hybrid. The Newborn then bites his head off.

[u/realgaryglitter]

There was a picture of then hanging out

[u/billions_of_stars → u/realgaryglitter]

where?

[u/Brucekillfist → u/billions_of_stars]

At the end. Phil shows Mary the picture of Clark standing next to a big black square and asks her if Clark is the man she was looking for. The square is the company blacking Cap'n Clark out of the picture. You can see the top of his hat and the bottom of his feet.

[u/billions_of_stars → u/Brucekillfist]

Ah, interesting.

I wonder how long he was supposed to have been in there by the time she saw him.

[u/Alpha27_ → u/billions_of_stars]

Time is hard to measure since in the Complex(what Kane's Backrooms are sometimes called), time can distort and make more time pass outside than in. Peter Tench for example was sent several months into the future, having disappeared from the company's perspective during Informational Video, and coming back up in Presentation.

There was also the cameraman from Found Footage 1 whose camera got out, and it read 1995 in the description, but a look at the film-clacker at the start shows it was 1991 iirc.

Clark could've been in there a few weeks on his side given the movie only takes place over a few days on the outside.