This would place the iPhone 7's thickness in line with the iPod touch or iPad Air 2, both of which are 6.1 millimeters thick. For comparison, the iPhone 6s is expected to be just over 7 millimeters thick, versus the existing iPhone 6's 6.9 millimeters.
So the iPhone 7's slimmer profile may not sound like much, but it'll make a difference to your pocket.
Furthermore, the reported slimness of the iPhone 7 comes at a likely cost to screen resolution, the report indicates.
The "Force Touch 3D" feature expected for inclusion in the iPhone 6s, where the phone can actually detect how much pressure you place on the screen and react accordingly, relies on a slab of glass over a printed circuit board.
Apple would eventually like to move to making Force Touch work on the iPhone line with glass on top of glass, which would enable a higher display resolution. But moving in that direction would make the iPhone 7 thicker than that 6 millimeter design goal.
In other words, the Apple iPhone 7 will be thinner than any iPhone before it, but it probably won't support the emerging super-high-definition 4K standard resolution, which outputs video at twice the resolution you're used to.
Given that Apple is also rumored to announce an update to the Apple TV on Wednesday that doesn't support 4K, either, it wouldn't come as a huge surprise that Apple is ignoring the format.