The iPhone 15 Pro Max could be thicker than the iPhone 14 Pro Max, but at the same time, it may also have a slightly smaller camera bump.
According to the leaker, the iPhone 15 Pro Max is 159.86mm tall and 76.73mm wide, giving it a slightly smaller footprint over the iPhone 14 Pro Max's 160.7mm and 77.6mm (6.33 inches by 3.05 inches).
While marginally smaller in height and width, the thickness for 2023 will be a bit more than in 2022, at 8.25mm to 7.85mm (0.31 inches).
Though the iPhone 15 Pro Max may be thicker, that's only if you account for the main body itself. Taking the camera bump into account, the total depth of 11.84mm is slightly smaller than the 12.03mm of the iPhone 14 Pro Max with camera.
The camera bump alone is 3.59mm thick, down from 4.18mm in the iPhone 14 variant, a difference of almost 0.6mm. In short, the camera bump won't stick out from the back as much as usual.
The source of the leak, "Ice Universe," has a good track record when it comes to iPhone details, such as the reduced notch in the iPhone 13. This, combined with earlier rumors, gives the renders a bit of credibility.
However, as with all leaks and rumors, nothing is guaranteed until Apple introduces a new iPhone on-stage in the fall.