Before digital cameras were widely available, every movie set with any kind of budget at all had a person who went around taking Polaroids of everything, sets, props, actors. This person's job was to play a real life game of spot the difference.

Scenes are often filmed over the course of days, or in the case of reshoots even months, then stitched together in the editing room post-production. It was the job of the continuity person to go through the previous days Polaroids and make sure that the chair was in the same corner of the room and that the actor's tie hadn't changed color.

Some mismatches inevitably slip through, particularly on lower budget pictures. Other times, the discontinuities are noted but unavoidable.( at least before the modern age of digital retouching ) Carol Burnett often told the story of how she had had surgery on her jaw shortly after what she had assumed to be the final shooting for John Huston's screen version of Annie only to be told a few weeks later that the studio had requested reshoots. She immediately reached out to Houston and told him that she now had a much less prominent jaw and the new footage would not match the old. Houston reassured her that everything would be okay with the direction just go out and look determined.

Carol Burnett has one of the best reputations in the entertainment industry for professionalism and could hardly be blamed for not anticipating the studio's last minute (Read more...)