This rider has hit the ground, and frantically scrambles in the dust to elude the flying feet of the bull. The men on either side of the bull are “rodeo clowns” who try to distract the bull, and keep it from injuring the fallen rider.
Thanks for commenting on the "decisive moment" here, Tim. The space between the flying rear hoof of the bull and the vulnerable rear end of the man is abstracted by flying dirt and dust.The image asks viewers to decide for themselves how close the fallen rider comes to disaster.