As for the build materials, this looks like just a sample mold, so the final chassis materials are still up in the air, but the separation lines top and bottom show that there might be at least two different materials used in the next iPhone. We are guessing a glass front and a largely metal back, based on all rumors so far, but it's still only speculation.
The iPad Mini sample, on the other hand, seems to confirm what we heard last week - that Apple's first foray into smaller tablets will be extremely thin, probably down to iPod touch levels, which will make it the thinnest tablet so far. Judging from the size-up with the new iPad next to it, this purported slimness is entirely possible, as long as these leaks carry some credibility. The iPad Mini mold actually matches the leaked case that we saw last week, down to the dock connector and the speaker grills, which we dismissed as the offputting blueish logo on the back looked rather P'shopped.