Nameless metal tile as an SMT resistor?
Hard to tell without a bit more context, but it could be a "zero ohm resistor" aka "link" or "jumper".  Basically not acting as a resistor, but given a R designation nonetheless.  These can be used where the designer isn't sure if a resistor is needed, and wants to try different options, where one board is used to make two slightly different products, or just to connect two traces where it was too hard to route without it.