And then suddenly there's this monster who hates the flash and the woman uses it to escape the monster... and by self-portraits.. it's like a Polaroid/instax thingy. So she had to go away and then at the end I think she was given flowers by some guy and that guy is apparently the monster or something. Please help!
Edit1: I think the reason why she came back to the apartment/building is because there was a news that everything's fine now. And no, it wasn't Shutter. It was about a monster not a ghost.
Edit2: It certainly wasn't any of the movies mentioned here.
Edit3: It wasn't Mimic/2 either. There weren't any kids in that movie (well I don't remember any) but I think the woman's Mother was present and there's another man I think or I'm probably making it up. sigh She has this collage of her everyday photos attached on her wall.
Edit4: I do remember something about that monster destroying the whole floor or probably the whole building. She escaped through an elevator. (I probably made up the elevator part, sorry).