Supposedly he loves her gestures and expressions. But can't tell she's literally the same person? I swear, this guy needs a psych eval, there is something broken inside his brain if he supposedly loves this girl that much and pays attention to her, but just make her slightly blurry with glasses and putting her hair up and she's like a stranger to him.
Also, FMC is just as brain broken, the guy she likes is pretty blatant about liking her, but instead of confessing she just surreptitiously lets him confess all his deepest thoughts to her in a kind of fucked up manner that is a bit of a betrayal of his trust.