On Sept. 12, Apple (NASDAQ:AAPL) announced three new iPhones: the iPhone XR, iPhone XS, and iPhone XS Max. The iPhone XS was essentially an upgrade of last year's iPhone X, and the iPhone XS Max is a much bigger version of the XS (representing a new screen size from Apple). The iPhone XR is a lower-cost alternative to the iPhone XS and iPhone XS Max, with a screen size that's in between the two. 

We'll get a sense of how well Apple is expecting these phones to sell when the company provides its financial guidance for the first quarter of its fiscal year 2019 on Nov. 1. 

A person holding an iPhone and looking at it.

Image source: Apple.

According to a recent report from TF International Securities analyst Ming-Chi Kuo, Apple's 2019 iPhone lineup is again expected to consist of three devices. And all three are expected to sport the same screen sizes and screen types (OLED for the XS/XS Max successors, LCD for the XR successor) as the current models. 

This means that next year's iPhones could look quite similar to this year's lineup. This wouldn't be the first time that Apple tried to get a lot of mileage out of the same basic form factor -- the iPhone 6, iPhone 6s, iPhone 7, and iPhone 8 families of devices all sported the same basic shapes and screen sizes. The key changes in between generations were in the specifications and features of the devices. 

If Kuo is right (as he often is), Apple will need to differentiate next year's iPhones on capabilities and not form factor. Here are some ways the company can do it.

The usual

With each new iPhone generation, Apple generally makes improvements across a number of vectors. For example, compared with last year's iPhone X, Apple says the iPhone XS has a faster processor, gigabit-class LTE, a better rear-facing camera, dual SIM support, zippier wireless charging, and enhanced water resistance. But the iPhone X and the iPhone XS -- save for the new gold finish on the iPhone XS -- look virtually identical. 

So with next year's iPhone models, I'd expect, at a minimum, improvements along these lines: another jump in processor performance with the A13 chip, even faster LTE, and another leap in camera capabilities (through a combination of sensor, software, and chip upgrades). Given how important camera quality and features are in the fiercely-competitive premium smartphone market, I hope to see Apple continue to make significant strides on that front.

The less-usual

Judging by recent history, Apple tends to introduce noticeable display-feature updates with every other generation of iPhones. For example, the iPhone 6 and iPhone 6 Plus introduced new displays, which were then recycled in the iPhone 6s and iPhone 6s Plus. Then, with the iPhone 7 and iPhone 7 Plus, Apple upgraded the screens to support the wider DCI-P3 color space. Reviews of the devices showed that color accuracy had improved dramatically from the screens found on the iPhone 6 series and iPhone 6s series. 

I wouldn't be surprised, then, to see Apple deliver a significant display upgrade with the successors to the iPhone XS and iPhone XS Max. I've previously written about how I'd like to see Apple deliver higher-refresh-rate screens to its premium iPhones, which would certainly qualify as a significant display-feature upgrade in my book.

There have also been rumors that Apple is looking for ways to reduce the size of the so-called "notch" on the front of the device. If Apple were to figure out how to do that without sacrificing functionality, it could be viewed as an attractive aesthetic improvement over the current iPhones. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.