How does Alan Hollinghurst use imagery in The Line of Beauty?

Imagery:

"Days like these had their design, their upward and downward curves: it would be unshapely to change the plan." Chapter 4, p. 110

"The double curve was Hogarth's 'line of beauty,' the snakelike flicker of an instinct, of two compulsions held in one unfolding movement." Chapter 8, p. 176