It's not an unusual coonfiguration, seen most often in the larger flight decks. The Vanguard with its enormous flight deck had this, I think the Comet may have done, and at least one of the V bombers had it. It gives each pilot his own thrust levers. Whether it is needed on the F28 I wouldn't like to say- the designer and builder thought so, but all the civil Boeings don't have it.
Why does the copilot need a letterbox in the front panel?