When Francis opens the Christmas card and jingle bells plays to annoy Ida but when Ida stabs him in the thigh with her knitting needle, the card drops beside Francis on the couch but in the next shot, it is on the armrest and in the next shot, the card is gone.
When Ida stabs Francis in the thigh for playing the Christmas card. Francis would've had a wound and he would've been bleeding but he did not bleed.
When the cigarette falls through Ida's dress you can clearly see that a piece of the dress was cut for it to fall through.