I agree re a lot of the themed dressing, but in this instance at least, I expect that style of dress has been chosen to meet a lot of cultural norms and expectations, while also trying (trying!) to look stylish.
In a strict Muslim country, it's less about wearing a kilt so you (think you) look Scottish and more about dressing in a way that won't actually offend your hosts.
That dress is not for me - and I wish someone would take and burn every pair of her plasticky, shiny (no doubt LI Bennett, so expensive) bloody nude heels. They are godawful.
The jewels are nice though.
Oh, and I'm in the "she looks tense/nervous" camp.