The poet is overjoyed on seeing the daffodils. It was 'Fluttering and dancing in the wind'. The daffodils are compared to birds that flap their wings and to humans who could dance.
The daffodils stretch along the lake like starts spread in the Milkyway. They seemed unending like the stars and were twinkling like the stars.
The poet says he saw more than ten thousand. It is a hyperbole as it shows exaggeration.
They were tossing their heads. The heads refer to the top part of the flower. They were moving and dancing in rhythm.
