By Benjamin Schwartz in the 12/11/23 print issue of the New Yorker:
On first looking at the cartoon, we go to the faces, because faces are so socially important to human beings. There are two: a woman, speaking; and her male companion, the driver of the car they are in, his face turned to listen to her. She is voicing an observation (usually a complaint) that is conventionally and stereotypically taken be to common in intimate couples in our society, that the addressee is turning into — becoming, in significant ways — one of their own parents.
In any case, what we perceive at first is the passenger telling the driver: You’re turning into your mother, with inchoative turn into ‘become’.
But then we take in the rest of the drawing, where we see — surprise! — an old woman, up against the hood of the car, her hands up in the air, her cane flying into the air; the car has run into her. The passenger is in fact observing to the driver that he’s driving into the old woman, using one of the senses of motional turn into, with a complement referring to the end-point of the turn.