When two words, clauses, or phrases stand close together and share the same part of the sentence, they are in apposition and are called appositives. 

In fact, an appositive is very much like a subject complement, only without the linking verb:

subject complement

My brother is a research associate.

appositive

My brother the research associate works at a large polling firm.

subject complement

Jean became a magistrate.

appositive

I have never met Jean the magistrate.