Daphne's mask can combine Daphne's powers with another persons power. It can also see Domino in the past using Daphne's memories. Bloom is the only other person to use Daphne's mask other then Daphne herself.
It is orange and shaped like a pair of wings with two holes for the eyes and various decorations. It looks like a masquerade mask.
When Bloom decides to go to Domino to find the Book of Fate that will allow her to find her parents, Daphne came into her dreams and gave her mask to Bloom, and told her that it would allow her to see Domino through her own eyes as she remembers it before the Ancestral Witches and Valtor destroyed it.