To identify these parts pictured above, Nowhereelse.fr used the images iFixit posted about the iPhone 5 teardown. As they point out — and you can easily identify in the image below — the leaked part carrying the part no. 921-0345-05 was spotted on the iPhone 5 motherboard, and it was related to one of the handset’s two camera flashes.
A quick search, though, revealed that the component found on the iPhone 5 motherboard and identified as part no. 821-1441-A, is the backlight module of the iPhone 5.
A comparison of the two components reveals small design differences indicating that the part leaked today is most likely intended to equip a next-generation iPhone. It remains to be seen which one.