Re: What are these harmonics?
Those just look like tap harmonics to me.
Let's say you're fretting the B string on the 3rd fret. Simply tap the string (over the fret bar, so the string is hitting it) 12 (easiest, but other intervals can work) frets up and release quickly.
Think about it. It's like hitting natural harmonics at the 12th fret. By fretting with your left hand first, you're just moving the harmonic node up the fretboard. However, the obvious effect is you can no longer touch the node whilst picking it, so instead you can tap it.
Imagine you formed a basic D chord. To create tap harmonics, tap the 12th fret on the D string, the 14th fret on G, 15th fret on B, and 14th on high E.
Just remember to tap over the actual fret wire, and release quickly.