A guy mirrors my facial expression?

Is it a good sign or it doesn't mean anything?

There's a guy in my school and I have a crush on him. We haven't talked or anything, but we smile at each other. Anyway, he always smiles exactly the way I do. Once I smiled very softly and so did he. But when I have a big smile on my face, then so does he. And okay, I understand with the smiling. But what has happened several times, is that I didn't even smile, I did this thing with my mouth, it's kinda hard to explain, but anyway, he did exactly the same thing. So does it mean anything?
A guy mirrors my facial expression?
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