Until you said that, I thought they meant the pin hole to eject the sim card - which had me confused, so I guess they actually mean injection moulding or something?
Yeah, they are the glossy circles that appear on injection moulded plastic parts. It's caused by the pins that quickly push the cooled part out of the mould.
Gotcha, thanks!
Yeah, it’s what pops the part out when it’s done I’m pretty sure. There is also the mark where the plastic was injected.