What does Ezekiel 1:21 mean?

When the creatures moved, the wheels moved. When the creatures stopped, the wheels stopped. When the creatures rose from the ground, the wheels rose too, because the spirit of the living creatures was in the wheels. Ezekiel 1:21 - Modern Text Bible

(This repeats the close connection between the creatures and the wheels, reinforcing the idea that they move as one, guided by the same spirit.)