A Clue Board
Much of the imagery in the film - particularly the mansion featured in the film - is reminiscent of both the Clue film and the Clue board game.
Agatha Christie
Much of the imagery in the film is reminiscent of the Agatha Christie's - whose novels inspired the film - novels like Murder on the Orient Express.
Knives
The many knives featured in the film - from single knives to the mosaic of knives - underscore not only the film's themes, but its tone and its twists and turns.
Marta's Coffee Mug
Marta's inherited coffee mug that says "My House, My Rules, My Coffee" lets viewers know that Marta has achieved the American dream and is now an independent woman.