The Hopi Indians are a very spiritual people and as a result many of the images on the pottery they made are spiritual images. Many of the pieces of ware contain images of Kachinas, which are a big part of the Hopi religion. Kachinas are the spirits that the Hopi ask for rain and good crop growth. Many bowls have been found buried next to the dead with food in them. This might suggest that the Hopis held a belief in future life.
Feathers are also a common image on the pottery.
It is thought that the feathers are symbolized as women's prayers. This is an excellent link for further information about the Hopi Indians and their culture. Adams, E. Charles, Miriam T. Stark, and Deborah S. Dosh. Jeddito Yellow Ware and Implications for Social Complexity. The University Museum of Archaeology and Anthropology, University of Pennsylvania, 1990.