This movie is similar to 'The Player' and 'Adaptation', a movie within a movie, which most of the comments seem to miss. All of the comments on this movie seem to assume that 'Matthew' is really a homeless person. The last part of the movie, however, indicates that Oliver is really Matthew Delacorta. You hear his fellow mates at the shelter saying he had a wad of $20's. You see him tip the diner waiter generously. This man has money. His new movie is supposedly named 'Diversion'. He mentions the stars in the movie to be his fellow shelter bums. In the penultimate scene, what is popping out of the computer printer is an article on a movie 'Diversion' with a picture of someone who looks like Oliver.
This explains the scene at the end, where he stares at her and she looks depressed, because she realizes he really is Delacorta and is not a homeless person she picked up. He really is staying at the shelter to soak up some atmosphere. Realizing their relationship was based on her fantasy, which no longer exists, he leaves. We assume that subsequently he makes the movie about that day and calls it Sunday. A nice twist to a well-acted flick.
This explains the scene at the end, where he stares at her and she looks depressed, because she realizes he really is Delacorta and is not a homeless person she picked up. He really is staying at the shelter to soak up some atmosphere. Realizing their relationship was based on her fantasy, which no longer exists, he leaves. We assume that subsequently he makes the movie about that day and calls it Sunday. A nice twist to a well-acted flick.