How does Iris Murdoch use imagery in The Nice and the Good?

Example of Imagery:

"The front door was wide open, framing distant cuckoo calls, while beyond the weedy gravel drive, beyond the clipped descending lawn and the erect hedge of raspberry-and-creamy spiraea, rose up the sea, a silvery blue, too thin and transparent to be called metallic, a texture as of skin-deep silver paper, rising up and merging at some indeterminate point with the pallid glittering blue of the midsummer sky."