Avengers: Endgame is awash with Easter eggs for fans of the comics, but one rather bizarre Easter egg was placed in the movie as an in-joke to the locals of one of the filming locations, meaning not many people will have spotted it.
When Banner and Rocket travel to Norway to recruit Thor for the Time Heist, they find him depressed over his failure to stop Thanos and wallowing in self-pity with Korg and Miek. Visible in the background of shots within Thor’s cottage is the distinctive orange and blue label of a bottle of Irn-Bru, a popular Scottish soda, and a reference to the scenes actually being filmed in St. Abbs, a small fishing village on the southeastern coast of Scotland, now adorned with a sign declaring it “twinned with New Asgard.”
The prominent positioning of the bottle in the shots means its inclusion was unlikely to have been an accident (unlike some other caffeinated beverage holders), and was intended to be noticed by any Scottish people watching the film. It’s possible it was also used as an extension of Thor’s heavy alcohol consumption (incidentally with Innis & Gunn, a Scottish beer), as Scots will swear by the drink as a hangover cure.
Irn-Bru (pronounced “iron brew”), colored a radioactive orange and with a taste that doesn’t relate to anything else, outsells Coca-Cola in its home country and is referred to as ‘Scotland’s other national drink.’ It actually does contain trace amounts of iron, too, which I once personally confirmed via a high school chemistry project determining exactly how much (0.000043g per liter, in case you’re interested).
Of course, Avengers: Endgame isn’t the first time the MCU movies have had a joke with their Scottish filming locations. During Avengers: Infinity War’s scenes in Edinburgh, Scotland’s capital, a sign on a chip shop can be seen offering deep fried kebabs. While the real shop is a different one, the joke of my nation’s habit of frying any food on Earth is well documented, and while I’ve never had a kebab deep fried, I can recommend pizzas and Mars bars being prepared in such a way, with Irn-Bru being a perfect accompaniment.