The design is based on a Sogdian textile fragment. Both the Sasanians and Sogdians were known for producing textiles with beautiful roundel style designs, often incorporating zoomorphic elements as you see in this design! These designs are simpler, although no less sophisticated, than the designs you see in Byzantine, Xazar, Viking, and Middle Eastern textiles towards the end of Late Antiquity and Medieval times. However, make no mistake! They are Iranic in origin!