1♦ showed 4+♦. Not necessarily unbalanced, but would only be balanced if 11-13 with at least 4 good diamonds (1N is 14-16 and 17-19 balanced opens 1♣).
Either player doubling 4♠ would be takeout. 3rd seat openings are "normal light".
How do you think the auction should end? Assume E-W are done.