“A ring of cottonwood trees cooled their heels in the wet ground, and overhead leaned together, then apart, making whispery swishing noises.” What is being personified?

A ring of cottonwood trees cooled their heels in the wet ground, and overhead leaned together, then apart, making whispery swishing noises. It made me think of Gossip, the game we played as kids where you whisper a message around a circle. You’d start out with “Randy walks to the hardware store” and end up with “Granny has rocks in her underwear drawer.”