When the couple is in the kitchen worried about seeing each other before the wedding, Nick, the photographer, enters the kitchen carrying a camera with a white Canon 80-200 mm L series lens. When he first turns to exit the kitchen, he has the same lens, then when he goes through the door the camera has an all black lens.
Near the end of the movie when Nick is looking at the photo board in Molly's office the headings for each photo section are a mirror image when the shot pans out.