https://www.cnet.com/news/the-2019-iphone-xi-imagined-in-renders-even-though-its-only-january/

The highlight seems to be the inclusion of a triple rear camera. Other phone manufacturers (such as Samsung and Huawei) have released triple-camera phones and persistent rumors say Apple may follow suit this year. The proposed design solution is a square camera bump, much wider than the bump on the iPhone XS.

OnLeaks has a history of rendering upcoming phones before their release, but since this one comes long before the next iPhone is expected (Apple usually announces new iPhones in September), he adds that the design may be subject to change. So it's best to take these renders with a grain of salt.