Other mistake: Talia has connected earlobes, but the child version of her does not.
Suggested correction: I think there are a lot more differences in appearance between Marion Cotillard and Joey King besides the ear lobes. They are different people after all. It's not a mistake to have two different people play the same character at a different age. It's inevitable.
Explaining why a mistake occurred doesn't change the fact that it's still a mistake.
It's not a mistake if nothing went wrong, though. You can't expect them to find a young actress that is completely similar in appearance to the adult version of that character. That you can see it's not really the same person, only younger, is not a mistake. I think something can be said about eye colour or hair colour, maybe, but earlobes, not so much. Their mouths and noses are different too; you can make a list of mistakes then. They can only get it as close as they can get it, so it's not a mistake.
You're literally admitting they don't look alike, thus creating a continuity gaffe... which is a movie mistake... and then trying to claim it's not a mistake. Yes, it's true that finding a child actor that looks the same would be difficult, but that doesn't nullify the fact that earlobes can't change that radically from childhood to adulthood. That's a completely different thing than face/nose shape, eye colour, and hair colour, which can in fact subtly change with age.
