Cut four 18-inch-long sheets of plastic wrap; fold in half lengthwise. Cover wreath with plastic wrap by pulling wrap through center and around wreath, overlapping plastic to cover wreath completely. Place on serving plate. Cover wreath with lettuce leaves.
In large bowl, toss shrimp, lemon juice and seafood seasoning. Arrange shrimp on wreath, using the natural curve of the shrimp to cover the outside edge of the wreath.
In small bowl, mix remaining ingredients; spoon into serving bowl. Place bowl of sauce in middle of wreath for dipping. Cover and refrigerate until serving.