I have gone through this WHOLE THREAD (I must be crazy) and I was totally convinced about Mary just a couple dozen pages in. And that's with hundreds/thousands of pictures missing! Her constant eye-contact with cameras is ludicrous. Even leaving out the posed group portraits, where I'll cut slack. It's the most obvious in gifs and videos where she smiles.... and holds it. It's not natural to smile widely and hold it when walking and (supposedly) interacting with people, making eye contact.
Her eye thing is also weird. I'm new to RD, coming not from sugar boards but from very well-mannered jewel/clothing/royal history blogs. No dishing allowed. I've always been struck by how wide-eyed and bright-eyed she seems to be despite her wide "warm" smile. Most people's eyes crinkle up a lot when smiling. It's part of what can make a smile look genuine.
What she reminds me of is a theater professor who lectured an amateur cast I was in on how to look alive on stage. "Open up your face! Let emotion show all over. Exaggerate! And open your eyes! Wider! People can't see subtle emotion from the back of the hall, so put on extra for them."
That's EXACTLY what Mary does. She pastes on a mechanical, long-practiced grimace, opens her eyes wide (helped by science), and poses. She's on a stage all of the time. Problem is, there's clearly nothing natural about it. Modern royal acting is like TV acting: up close, in people's faces and on their screens, where even the smallest facial and eye movements can express a world of emotion. But Mary puts it on a like a trowel, over-acting as if for an audience of thousands, and focusing only on cameras. Her head's in that game, not in the occupation of actually being a worthwhile, meaningful crown princess.