There's a similar message at the end of Les Diaboliques - another of my all-time favourites which I highly, highly recommend if you've not seen it. Just make sure you watch the 1955 original, not the ghastly mid-1990s Hollywood remake.

Here are my thoughts in more detail (don't worry, I don't spoil the ending).

https://medium.com/fan-fare/les-diaboliques-best-twist-ever-6a0855648571