The crabs, corn, and container of Old Bay Seasoning are made of white chocolate. The sand is crushed graham crackers and vanilla wafers. The mallets are fondant. The entire cake is edible!
The couple commissioned a comic artists friend of theirs (at http://www.viruscomix.com/subnormality.html) to create a picture of their wedding party. The wedding photographer then had everyone recreate the pose. I think it was done very well.