Don't know if anyone else has mentioned this, but with the last repetition of the word knife, the volume is turned up so that final 'KNIFE' is a bit louder than the previous ones. Also, when that final 'KNIFE' is uttered a bell rings almost simultaneously. This makes the audience ( and Alice) just a bit more startled.
The bell rings when the shop door opens and a customer enters to purchase a newspaper. You can see him in the background when the shot switches to a wide angle and you see Alice's family and the shop in the background.
