Masks were deeply symbolic, and refelctive of the Sugpiaq spiritual worldview. They were primarily used in ceremonies like the winter Hunting Festival or the Feast of the Dead, which were integral parts of the Sugpiaq spiritual practice. After being used in these festivals, the masks would then be broken or put in caves. There is a symbolic motif in many Sugpiaq and Yupik masks that highlights the spiritual significance of hands. You can often see holes in the hands, and this reflects the belief that your hands created a passageway between the physical and spiritual worlds. In Looking Both Ways: Heritage and Identity of the Alutiiq People, a story is told by Stepan Britskalov about how he encountered the spirit Nunam Sua and she drew a circle on the back of his hands and inside he could see all the animals. It has been interpreted that these holes on the hands represent the connetion between the spirits and humans, and how the spirits let go of their grasp on the animals and return them to the hunters on earth (pg.193).
Crowell, Aron L, Amy F. Steffian, and Gordon L. Pullar. Looking Both Ways: Heritage and Identity of the Alutiiq People. Fairbanks: Univ. of Alaska Press, 2001. Pg 193-205