When Apple (NASDAQ:AAPL) first launched the iPad Mini 2 -- its first small tablet with a Retina Display -- one of the major criticisms of the device is that the display, though sharp, was not all that great.

DisplayMate's Raymond Soneira performed an extensive analysis on the iPad Mini 2's display (which was also recycled in the iPad Mini 3) and his assessment of the display was that it was merely "good." Other, lower-cost devices, such as the Kindle Fire HDX 7 and the 2013 Nexus 7 received "very good" scores.

For such a pricey, premium tablet, the use of a subpar display was quite disappointing.

However, with the just-launched iPad Mini 4, Apple introduced a display that Soneira rated as an "excellent" display -- beating out the displays found on both the iPad Air 2 and the brand-new iPad Pro.

In this article, I'd like to explore what the various advancements in the iPad Mini 4 may mean for the iPhones that are expected to launch in late 2016.

iPhone may get the anti-reflective coating
With the iPad Air 2, Apple introduced a new anti-reflective coating for the display. According to Soneira, "reflected ambient light washes out the on-screen images, reducing both their contrast and saturation."

This coating, per the display expert, leads to a 62% decrease in reflectance, "significantly" boosting the "actual on-screen image contrast" seen in typical ambient light environments by "an incredible factor of 2.6X."

He also says that this anti-reflective coating also leads to an improvement in on-screen color saturation.

Given that Apple is now using this technology (to great effect) on its relatively low-priority iPad Mini 4, it seems almost a no-brainer for the company to try to leverage this technology on the iPhone 7/7 Plus in order to dramatically improve display quality.

Color accuracy may be set to improve substantially
According to DisplayMate's tests of the iPad Mini 4, iPhone 6, and iPhone 6 Plus displays, the iPad Mini 4 offers even better color accuracy than the displays on Apple's flagships (note that the 6/6 Plus displays are the same as the ones on the iPhone 6s/6s Plus, respectively).

Indeed, in terms of absolute color accuracy, the iPad Mini 4 display delivers a much lower average color error than either the iPhone 6/6 Plus displays as well as a much lower maximum error.

iPad is lower priority than iPhone, so expect nice things from iPhone 7/7 Plus
Generally speaking, iPad is a lower priority product for Apple than the iPhone is. After all, iPhone brings in many times the revenue and gross profit dollars that iPad does, and the smartphone market itself is much more competitive than the tablet market is.

It's also worth pointing out that Apple tends to upgrade the displays in its iPhones during "new number" years. Since such displays need to be "top tier" for two years in a row, Apple tends to deliver substantial improvements when it endows iPhone with new displays.

If Apple was able to include such a nice display in the iPad Mini 4 -- a product that's probably lowest priority among the three flagship iPads -- then it seems reasonable to expect even greater advances in the next-generation iPhone displays.

Apple will need big advancements to stay competitive
Although Tim Cook once publicly said that Apple wants to have the "best" displays and that he believes that the company has them, the reality is that the displays found on Apple's current iPhones are great but not the best among high-end smartphones.

DisplayMate tests of the display on the Samsung (NASDAQOTH:SSNLF) Galaxy Note 5 show that it bests the iPhone 6/6 Plus displays in terms of color accuracy and contrast. I suspect that the delta between Apple's best and Samsung's best will widen with the release of the Galaxy S7 in the spring. 

In order for Apple to regain display leadership with the iPhone 7/7 Plus generation of phones, it will need to deliver some big display enhancements.

Ashraf Eassa has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Apple. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.