Interesting touch, and very smart actually given how many people had their backs crack just from temperature variations on whatever surface they put their Nexus 4 down on. Hopefully that lifts the glass off any surface a bit. Flip side is that looks like it'd be a fitment problem for most cases on the market already.
i dont think theyd change the desing for that. not worth it.
They probably have a whole variety of reasons. IMO raising the speaker off flat surfaces would be a perfectly good reason because it's completely muffled when you put the phone down on its back. They wouldn't change the hardware just for that, but it'd certainly help.
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