How does Donna Tartt use imagery in The Secret History?

Imagery:

"The woods were deathly still, more forbidding than I had ever seen them - green and black and stagnant, dark with the smells of mud and rot."

"It was one of the worst nights of my life. The house was filling with people and the hours passed in a dreadful streaky blur of relatives, neighbors, crying children, covered dishes, blocked driveways, ringing telephones, bright lights, strange faces, awkward conversations."