The mechanical stabilisation is right there in plain sight where one side of the magnet is clearly resting on the other magnet (physically in contact). Anyone who’s played around with magnets that are heavy and too weak to flip themselves around will not be satisfied with this video. It could be explained by two South Poles opposing each other.
Technically it can be done with an array of magnets with opposing polarities.
Without more details from on this video's source and legitimacy, one could argue that an array of magnets is hiding under the 'single magnet' cover plate.
I am not saying this is a hoax, but as exciting as this seems we just have to wait it out for more replication publications to make that call.
How?
[0] https://en.wikipedia.org/wiki/Diamagnetism#/media/File:Diama...
To which I then added:
"I am not saying this is a hoax, but as exciting as this seems we just have to wait it out for more replication publications to make that call"
It last been a little over 2 weeks since the first pre-print from Korea University.
The hashing out of a fabrication process with less impurities will be a long one. My point is not that everyone is pulling a con, my point is that we need to wait it out.
TL;DR: Normal magnets have two poles, and will try to flip themselves around to achieve a lower energy state. You cannot levitate a normal magnet on another magnet without mechanical stabilization. Superconducting materials actively repel all magnetic field lines and can achieve levitation without external stabilization.