Have each guest bring a picture of a favorite memory with the bride or groom to display and then give to the bride at the end of the shower. OR use this idea to display pictures of the bride and groom for family
photo display for a party - double sided so they can spin a little. / you could do these right beside the hanging table. Maybe use streamers in your colors to hang from the exposed trusses to kind of add color and a block from the big empty space.