You know what I hate in books? When an author says: “a look she didn’t recognize crossed his face.” There are a dozen different variations on this but the essence is: someone is feeling something but the first person protagonist can’t make sense of it.
It’s understandable – the book is written in first person so the reader is limited to what the protagonists perceives.
But I don’t like it because I can interpret the expression even less than the protagonist (by virtue of not even actually seeing it). Saying that the protagonist doesn’t understand it frees the author from having to describe the expression or the emotion. But what’s the point in telling the reader something exists that you’re not even going to attempt to explain or describe?
I think I find it more frustrating because in real life it’s not often you encounter an expression you can’t read. People can lie with their expressions. You can see something and not understand what’s driving the emotion. But very rarely is there a flicker of emotion that you register but can’t interpret.
And I get it, an author might want to say something like that to tell the reader that the person in question is keeping secrets; to create a sense of mystery or intrigue. But I think the unrecognizable expression is a bad way to go about that.
The only time it really works is when it’s not working at all; when the expression is described but not understood by the protagonist, or when a line of dialog or a moment makes it abundantly clear what the expression actually is but the protagonist is too dense to get it. Those are usually moments when a look of longing or desire crosses a guy’s face and the girl hasn’t got a clue. That works.
But please stop writing about expressions the main character doesn’t recognize. It isn’t any fun for me.