Pauno's Bakery is sponsoring the Festival of Light by providing Commemorative Lanterns to float on the waters. The festival commemorates the dedication of the Tower of Light, Elysea's half of the Tower of Eternity. Without Lady Ariel and the Tower, Elysea would have had too little Aether to survive post-Cataclysm. You brought back the stolen Lanterns, and Pauno gave you a reward.