It's well-known that Apple (NASDAQ:AAPL) is planning to launch three new flagship smartphones this year. By far the most exciting of the bunch is the company's rumored premium iPhone with OLED display.

That phone is supposed to come with an all-new form factor as well as a slew of new features, such as an OLED display (for improved picture quality), advanced cameras with, among other things, 3D-sensing capabilities, and more.

Apple iPhone models in a "mosaic" pattern.

Image source: Apple.

However, this phone is expected to be above where its flagship devices have typically been priced, meaning that Apple still needs to deliver compelling products at more familiar -- and, obviously, more affordable -- price points.

To that end, Apple is expected to launch direct successors to last year's iPhone 7 and iPhone 7 Plus, respectively.

Not much has come out about these devices, but a fresh new leak from noted leaker Sonny Dickson (provided to 9to5Mac) changes that.

Ooh, shiny!

The images published by 9to5Mac show two major changes that Apple seems to be planning for the iPhone 7s Plus. The first is that the rear of the device is made up of glass rather than aluminum as in the prior-generation iPhone models.

This gives the device a sleeker look (i.e., what Apple seemed to be going for with the Jet Black versions of its iPhone 7 and iPhone 7 Plus smartphones), and it also appears to allow for Apple to eliminate the antenna lines on the rear of the device.

9to5Mac deduces that this is because "glass allows antenna signals to freely pass through the material, whereas aluminum blocks most of the signals."

That's not all, though. Based on the images, the frame of the device is highly reflective, perhaps indicating that it is made up of stainless steel rather than aluminum.

A nice improvement to the iPhone 7 design

Although the iPhone 7s and iPhone 7s Plus surely won't be anywhere near as impressive as the OLED iPhone in terms of aesthetics, the images from Sonny Dickson do point to a pair of devices that will look quite a bit more impressive than their predecessors.

This aesthetic makeover, coupled with critical specification improvements to the underlying technology of the device such as a fast ProMotion display, a zippier A11 Fusion chip, better camera subsystems, wireless charging, and potentially more, could make the iPhone 7s and iPhone 7s Plus compelling devices at their respective price points.

In terms of the internals, the upcoming iPhone 7s series of devices have the potential to be at least as big of upgrades over the iPhone 7 series as the iPhone 7 were over the iPhone 6s.

Per Apple on its most recent earnings call, sales of the iPhone 7 series phones were "up strong double digits year over year," suggesting that customers were more interested in the iPhone 7 series during this product cycle than they were in the iPhone 6s series at the same point during the last product cycle.

Now, I don't think the iPhone 7s will see such robust growth again since many buyers will likely be attracted to the premium OLED iPhone 8, but this year's iPhone lineup in aggregate has the potential to do very well. Much of that potential is due to the premium OLED model, but I think the 7s and 7s Plus could do respectably in the marketplace, too.

Ashraf Eassa has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Apple. The Motley Fool has a disclosure policy.