Engadget editor Richard Lai recently published an article containing renders purportedly of Apple's (AAPL -0.21%) upcoming iPhone 8 smartphone. The render is based on, Lai says, "a highly detailed CAD file" of the device that came courtesy of a "reliable source in the accessory industry."

You can check out the renderings by going to the Engadget article itself, but there's nothing terribly surprising here: the device will feature a "glass sandwich" design (as has been rumored for a while now) and the camera bump will be oriented vertically rather than horizontally (also rumored for a while). The bump, Lai says, will contain both the True Tone flash as well as a microphone.

Apple's iPhone 7 Plus in Jet Black.

Image source: Apple.

Beyond the renders, Lai says that his source offered up some information vis-à-vis display sizes. Apparently, the 4.7-inch iPhone will see its display size bumped up to 5-inches, while the 5.5-inch iPhone Plus will see its display enlarged to 5.8-inches.

I'm not ready to buy that last bit of information, though, as the current word from generally reliable KGI Securities analyst Ming-Chi Kuo is that the iPhone 8 will have a 5.8-inch display with 5.2 inches of display area (the rest is expected to be taken up by the so-called "function area"). The iPhone 7s and iPhone 7s Plus are expected to retain the same display sizes as the current iPhone 7 and 7 Plus.

Larger iPhone 7s/7s Plus likely wouldn't be ideal

The reason that the iPhone 8 seems so exciting is that Apple is expected to pack a large display into a relatively small device footprint. Indeed, for their display sizes, the current iPhone 7 and iPhone 7 Plus have relatively bulky physical footprints, which makes them less wieldy than they could be (as evidenced by what some of Apple's competitors are doing).

If Apple were to enlarge the displays with the direct successors to the iPhone 7 and iPhone 7 Plus, then either the devices would become even more unwieldy (at the very least, the iPhone 7s Plus would be), or Apple has found a way to offset the footprint increase that larger displays would engender.

The problem with the former is that this would simply be detrimental to the user experience -- something that Apple absolutely shouldn't be OK with. The issue with the latter is that it's hard to imagine how Apple could pull that off with designs like the current ones.

Apple might be able to save some space by narrowing the side bezels a bit, but unless the company can dramatically reduce the size of the circular Touch ID sensor on the bottom bezel, then the company wouldn't be able to shrink the top bezel without eliminating the symmetry that exists between the top and bottom halves of the phones.

Realistically, then, I expect Apple to stick with largely the same form factors as the current iPhone 7 and iPhone 7 Plus for the "standard" iPhone models, with perhaps the use of glass backs (as has been rumored in the past) instead of aluminum.