The couple on the left of the painting represent physical love; sex and lust. Hence, they are wrapped in each other. They bring flowers to Venus, praising love as most couples do. Notice that they have wings, and their feet are hovering off the water; romantic love is "airy" and unrealistic.
The pure maiden on the right represents intellectual love; wisdom was considered feminine by the Greeks, and a solitary quality. She gifts Venus with a cloth, not just for modesty. She is putting on the "veil