What details of the shepherd's description seemed distinctly idealistic in the nymph's reply to the shepherd by Sir Walter Raleigh?

In the nymph's reply to the shepherd by Sir Walter Raleigh, the shepherd idealistically describes a world where love will never fade and where eternal happiness awaits. The nymph's response contrasts this idealism by pointing out the transient nature of beauty and love, highlighting the inevitable passage of time and the impermanence of earthly pleasures.