SIMs can get a bit scratched anyway, just by inserting them into the holder. Things look OK in the pics. The easiest way to prove this, is if you can borrow another phone with a SIM. Put your SIM in another phone, and if it still doesn't work, the SIM could be duff, get your carrier to send you a replacement SIM. Also try putting another SIM in your phone, and if that doesn't work, then it's very likely the phone is stuffed.
Also if it's the SIM is duff and can't be read, the phone might show something like "SIM error" or "Insert SIM".