The focus of the change depicted in their photos seems to be what they're calling a "rough & bent" condition resulting from the manufacturing process. It appears that the top case is rendered less-than-perfect in manufacturing, and as a result doesn't sit completely flush when the phone is assembled. They also claim, according to their "OEM sources," that the process has been adjusted to successfully remove this imperfection.
Apple intended to sell a white iPhone at the initial launch, only to announce that it would be delayed by a few weeks and eventually several months. Since then, sites like WhiteiPhone4Now have offered patience-deprived customers a way to bring a little #ffffff to their iPhones without delay.
In the meantime, Apple's workers are obviously fixing the solution. Good luck to all of them.