I don't like to follow the predictable, cliched line, but quite honestly the parallels with the D and D of Windsor get stronger every day.
In a biography of Wallis (I think it might have been the Andrew Morton one) he includes a picture of the pair in the 50s, attending some kind of ball in France. The Duke has his usual downtrodden, pathetic whipped-dog expression and Wallis has almost exactly the same expression as Meghan when she's 'hissing' sharply at Harry (or other unfortunate minions). She's saying something to him and Andrew Morton captions the photo 'Wallis has a few tart words for David' or similar. Will try to find this photo....if I can.
I have a terrible Resting Bitch face...and I have to make an effort to look at least neutral on photos, so I get why someone in the public eye needs to be mindful of their facial expression and it must be exhausting. But even so, the contrast between Meghan's gushing public persona and her pretty scary demeanour when she thinks no-one's watching is striking to say the least! There doesn't seem to be a happy medium - just a relaxed vibe between them - it's either full-on beaming and PDAs, or that narrow eyed intense glare.