This exercise is from the Core Skills section on Harmonics.

Natural harmonics occur along open strings at certain points. In our previous exercise we played the 3 easiest natural harmonics on the high E string.

Now we will strum harmonics across all 6 strings. Notice that they all occur in the same places. This is a handy thing indeed because once you know that harmonics occur in the same places for each string, it makes it much easier to find them! It also means that you can strum across them, like we do here.

Once again we stick to the harmonic locations at the 12th, 7th and 5th frets. These are the most commonly used harmonics, and easiest to do.

Rest your 3rd finger lightly across the strings - just over the fretwires. Remember - don't push down on the strings. Strum and release your finger, and you should get the harmonics! Make sure your finger releases quickly, and also that it is not at an angle. It should run straight along the line of the fretwire. Leaving the harmonics to sound out will give you time to move your finger to the next fretwire position ready to do the next harmonic strum.