I wonder if the Apple 338S120L might be the M7? It's about the right size and proportions, assuming the illustrations and comparison between the A7 and M7 in the keynote video were to scale. Alternatively, I suppose it could be an replacement for the Apple 338S1117 (Cirus Logic audio codec) from the iPhone 5, assuming the Apple 338S1216 is the replacement for the Apple 338S1131 (Dialog power management) from the iPhone 5.
I also notice that the gyroscope chip (STMicroelectro
nics L3G4200D) that was in the iPhone 5 seems to have vanished.