When Betty is first introduced to the large cast iron stove, it has two upper doors decorated with what vaguely look like eyes, giving the stove a facial appearance. One of these doors falls open when she says to the stove that they will not be getting along. Then as she turns to leave, the stove is shown from a different angle and that door is closed, even though she has not had time to close it.
The car's driver-side window is most of the way rolled down as the car limps on its flat tire into the driveway, then the window is half-way up as Bob gets out.
Cooked eggs would have been served on the train ride, yet the egg that breaks on the coach floor is obviously runny and therefore raw.
Cleopatra the pig has a string attached to its hind leg, probably pulled by its handler off-screen.
When Betty is with her baby in the taxi, the baby makes no moves on its own and its facial expression does not change even when it is fussing. The baby is obviously not real.
In the scene where Betty returns to Bill in the end, she's standing outside of a taxi and holding their baby. The taxi driver also gets out, and she hands him the baby as she walks off-screen. Directly to his right, in the side window, the boom mic is very clearly seen. First, it comes up from below, stays in the center, then flies up beyond the window as Betty walks away (to catch her dialogue).