Cartoon showing the 3D morphology of the Orion A magnetic field. The bent gray cylinder and the red vector depict the Orion A filamentary structure and the mean 3D Galactic magnetic field in the region, respectively. The blue arrow shows the 3D magnetic field morphology of the cloud and is consistent with the B_∥ and B_⊥ observations shown in Fig. 1. Top panel: projection of the cloud onto the plane of the sky. Middle and lower panels: different viewing angles of the cloud. The black arrow denotes the direction in which rotations of up to 50° may be possible.