The diagram is examining your understanding of the motor effect. In particular, can you analyse problems involving a single current-carrying loop immersed in a uniform magnetic field.
The axis PQ represents the axis of a crude motor. We sometimes refer to the orientation of the loop using analogue clock hands.
In the horizontal plane, the loop can be described as the 3-o'clock position, and after 90 degrees rotation into the vertical plane, it can be described as the 12-o'clock position.
Does that help you visualise the rotation of the loop?