Maybe the second video in this post could help you understand: https://community.simplefoc.com/t/magnetic-field-viewers/4283?u=vipqualitypost
The field is “transferred” from pole to pole, causing the magnets to trail along, creating the motion. In your image, maybe it is too simplified. In order for torque to be made, you do have to the 6-step motion continuously, and with a specific relationship to the position and speed of the rotor, otherwise you will not generate torque.