This is air layering propagation at work, where the mature tree or plant is cloned from a stem that is still attached to it.

Q: I am interested in refining my air layering skills. I have watched many online videos, and I have had very good success with citrus trees such as lemon, lime, and mandarin orange.

Air layering is not an overnight process, as it can take weeks to a few months to grow enough roots to be able to cut the new plant from the mother plant.