The Eight Auspicious Symbols represent the Eight Qualities of the Buddha. Here is a brief explanation of how each quality is symbolized.
Excellent Lotus Flower:
The purity of the Buddha’s mind
Golden Wheel of the Dharma
The Buddha’s unending activity of training beings in the path of liberation
Great Victory Banner
The Buddha having conquered all negativity and limitations
Inexhaustible Treasure Vase
The inconceivable blessing of the Buddha’s presence
Precious Parasol/Umbrella
The universal respect, which beings feel for the Buddha
Precious Right-turning Conch
The all-pervading call of the Buddha’s teachings
Two Goldfish
The Buddha’s eyes and, therefore, his perfect wisdom and also a symbol of royalty
Glorious Knot
The tremendous love and compassion of the Buddha and the never-ending continuity of the teachings, also longevity, the eternal nature of things and the interrelatedness of wisdom and compassion