That looks like some bit of fluff has worked it's way into the phone and shorted the power terminals causing excess current flow.
"at least not the i9100, proper version.
If it is an SII then it will be one of the fudged carrier specified ones that American carriers are so fond of.
All of it is positioned incorrectly, and as a previous poster stated, it is NOT a Nexus, as that has a 5MP camera."
Absolutely, I have a genuine one right here in front of me with the back cover off and can confirm that the layout of the MicroSD, SIM and *MP camera differ.