If the electromagnet is producing a north pole as shown in the digram the magnetic field due to the electromagnet is going into the disc and is weaker the further away the disc is from the poles of the electromagnet.
I do not know the exact shape of the eddy current loop but I do know that the direction of the eddy (induced) current will be such as to produce a south pole as shown in the diagram.
This is Lenz's law in action as that induced current is trying to oppose the motion producing it which is the rotation of the disc.
You can think of it as the induced south pole on the disc attracting the north pole of the electromagnet and so trying to reduce the speed of the disc moving away from the electromagnet.
There is an equivalent north pole induced on the left hand side of the electromagnet which is repelling the north pole of the electromagnet , again trying to reduce the rotational speed of the disc.
On the other side of the disc there are induced currents interacting with the south pole of the electromagnet again trying to reduce the rotational speed of the disc.
There are equivalent forces on the electron magnet trying to move it in the same direction as that of the disc.
This video of Arago's disc is one of many video available on the Internet to show this effect.