Flux is the amount of magnetic field passing through an area. The "X"s represent a magnetic field going into the wall. The arrows on the ring to the left represent a current flowing counterclockwise, which causes a magnetic field that should go in to the wall. Since the magnetic field is going the wrong way, the flux is "weird". "Weird flux but ok" is a pun of the saying "weird flex but ok", which means someone is bragging.