As Brownlee emphasises, it’s a mock-up constructed from everything we know so far about the iPhone 7 Plus / Pro or whatever Apple’s flagship device will eventually be called.
So while it might be reasonably accurate, it would be wise not to take any observations as gospel.
With this in mind, the most noticeable difference compared to the previous generation is the less prominent antenna bands, which reportedly won’t wrap around the back. Additionally, there’s no headphone jack. Instead, we’ll likely get the single Lightning port and two speakers.
And then of course, there’s the dual rear-facing cameras. While you can speculate on what specific features Apple will pair with such a configuration, the simple fact of the matter is it’ll allow the phone to capture more data with every shot, be it for adding fancy visual effects or just providing an alternative image (say a wider / closer shot).
Brownlee’s video raises several more important points, so be sure to give it a watch if you’re thinking of upgrading this year.