Check out this photo of the iPhone 13 dummies showing all four models. Dummies do not work like phones, they just represent the physical dimensions of a device, which is useful for designing and testing cases.
There is not much to see, Apple will reuse the design in the 12 series with only minor changes. You may have already noticed that the iPhone 13 and 13 mini have switched to a diagonal location for the rear cameras instead of vertically.
Dummy devices: iPhone 13 Pro Max, 13 Pro, Vanilla 13 and 13 mini
Sonny Dickson, who posted the photo, says the iPhone 13 Pro Max is slightly larger. In fact, all models are expected to be slightly thicker (by a fraction of a millimeter) and also have thicker camera bumps. This is partly due to the larger batteries and partly to the upgraded cameras.
According to the analysts of all four models, sensor shift stabilization will be TrendForce. The ultra-wide module found on all four iPhones will also get an enhanced lens (6P) with autofocus. Only the two Pro models have LiDAR, which can also be seen on dummies.
With dummies already in the hands of caseworkers, you can bet that there are already more iPhone 13 cases for sale on certain sites. Here is an example:
In any case, Apple will reportedly try to return to a September revelation after having to push it back a month last year due to the pandemic. It is not set in stone and the launch can also be pushed back this year (semiconductor shortage does not help things).