How does Patricia Highsmith use imagery in The Talented Mr. Ripley?

Imagery:

"Tom swung a left-handed blow with the oar against the side of Dickie's head. The edge of the oar cut a dull gash that filled with a line of blood as Tom watched."

Then he went into the bathroom. The old rusty showerhead sent a jet against the shower curtain and another jet in an erratic spiral that he could hardly catch to wet himself, but it was better then sitting in die filthy tub.