The floats come in two varieties: yama floats with platforms decorated to resemble mountains and hoko floats dominated by tall wooden poles originally intended to summon the Plague God so that he could be transformed into a protective spirit through music, dance and worship.

UNESCO: Culture

So it must have given Gabriel a contemporary appeal to viewers at that time, and the fabric is dominated by an enormous dianthus flower, said to be the flower of God.

WSJ: Jan van Eyck | 'The Annunciation' | Old Subject, New Approach | Masterpiece | By Richard Cork