The giant Pro Max features a similar design as last year, but the new camera module on the non-Pro models is a big change.

A leak has revealed four dummy units representing the design of the upcoming iPhone 16 series. The
Pro Max device is huge, but the non-Pro models feature a new camera module design.
These designs are consistent with previous leaks, so we are confident in their relative accuracy.
Despite Apple's strict security measures (well, certainly tougher than Google's), even the mighty Cupertino company can't stop the leak. Today I would like to share with you a very important example. This is a set of four dummy units representing what we think the upcoming iPhone 16 series will look like.
Just to be clear, these are definitely dummy units (via X user Sonny Dickson). A clear clue is the camera lens. Each lens is the same size, but this is not true for the working model. That said, what you see here may differ from what the final retail-ready version of the iPhone 16 series will look like, but the gist is probably pretty accurate.

Perhaps the first thing you'll notice is that the iPhone 16 and 16 Plus dummy units feature a redesigned camera module. It looks like a combination of the iPhone X's camera (which had two lenses stacked vertically inside a pill-shaped module) and the modular design of the current iPhone 15 series. I don't know how I feel about that yet, but it's definitely a change.
Next, you'll notice that the iPhone 16 Pro Max on the far left looks smaller than the others. Featuring a rumored 6.9-inch display, this will be the largest Pro Max ever. This is not a significant change, since the 2023 iPhone 15 Pro Max had a 6.7-inch display.

However, apart from these two notable changes, there isn't much difference here. We would expect some models to see new buttons (perhaps for camera control), but these dummies don't seem to have them integrated. Otherwise, expect a new chipset for the Pro models, some new AI tricks in iOS 18, and other traditional spec upgrades.
We expect the iPhone 16 series to be released in September. So there's still a long way to go and many more leaks before it actually hits the market.