Why does GIllian’s face she made during David’s speech is such an issue?

Lol! It’s more the face she didn’t make that is an issue. Issue isn’t the right word, though. Let’s say that it’s telling. Trying so hard to make no face at all and not letting out one feeling about it just show that you do have feelings. It’s the same when you call someone your platonic friend. It means he’s not your platonic friend. Reversed psychology, you know?