CAD renders of Apple's next iPhones may have already appeared, but so has a prototype showing the iPhone 13 mini's camera design. The design will probably reflect the iPhone 13's too, which shows that Apple has switched to a diagonal arrangement, for some reason.
https://www.notebookcheck.net/Alleged-iPhone-13-mini-prototype-leaks-with-a-revised-camera-design.534134.0.html