Engadget is reporting on the difference in thickness between the white and black iPhones.
What's important for our purposes is the way this image highlights the power of contrast. You'll probably remember from your university class on perception the way that the lighter or darker environment surrounding the piece of the lead impacts our perception of it - it appears darker on the right side. Those unconvinced by gadget blogs may prefer being reminded about Richard Russell's "The Illusion of Sex":
Two androgynous faces, distinguished only by the amount of contrast in each image. One appears convincingly female, the other convincingly male.
Look back at the Engadget image. What's interesting is that the right portion of the lead still appears darker. The illusion persists, even as we're well aware of it.
Persistence is one of the more fascinating aspects of illusion, because cognitive illusions are no different from visual ones in this regard. I sometimes think that the only difference between the two is that we recognize and accomodate the importance of our physical limitations, while overlooking and underplaying the importance of our cognitive ones (an idea popularized by Dan Ariely at the end of his recent TED talk).
That is to say, we'll gladly build staircases to help reach higher ground, and craft clothing to protect us from the elements, but the best we can come up with is "just be rational" when it comes to helping us reach better decisions and protecting ourselves from cognitive error.
So I've started working against that. I've captured the sentiment within the link below, which resonates more and more deeply each time I read it.
Designing social structures that work with human limitation to shape better decisions for the future
