This is a really strange and surprising effect. When you drop an earth magnet through a copper pipe it appears to slow down falling and spinning at a lower rate than it should.
The falling magnet induces a current in the copper pipe and, by Lenz’s Law, the current creates a magnetic field that opposes the changing field of the falling magnet. Thus, the magnet is “repelled” and falls more slowly.
You did not understand, it is not a big deal. Just get hyptnotized once more by this amazing and weird physical phenomenon!