For starters, both the iPhone 16 Pro and 16 Pro Max have larger screens ... If you have an iPhone 13 Pro and the battery health is still good, it makes sense to wait another year to upgrade.
Also on the design front, one source claims that the iPhone 17 Pro Max will be available in one of the three colors pictured below. These, from left to right, are apparently dubbed Dark Green ...
There’s also an outside chance that we’ll see an iPhone 17 Ultra, either instead of or as well as the iPhone 17 Pro Max. This would ... namely Dark Green Titanium, Teal Titanium, and Green ...