You fell victim to the horrible inconsistencies of harmonics notation. There are lots of ways of notating them, for example:
- Notating the actual sounding pitches (which is, in my humble opinion, the only good way to do it).
- Notating the open strings that need to be sounded, and placing a number that says at which fret the harmonic needs to be sounded somewhere around there.
- Notating the open string that needs to be sounded with a normal note head, and the actual pitch with an empty diamond note head (not good, this works well on the violin but it's a mess on the guitar where you can sound multiple harmonics at once).
- Notating the open strings that need to be sounded and just placing a circle above the note heads, saying nothing more. (Which is even not a sufficient information!)
- Any other confusing and useless notation you can possibly think of.
As Tim says, your example is the second case here (so the actual pitches are A-E-A). However the mess is so confusing that in some pieces, people actually just make something up, because they have no idea what they should really play. (This happens a lot with pieces by Villa-Lobos who apparently liked to use the option 4. Try to have a listen to the very end of his Etude no. 1 or to the cadenza of his guitar concerto, on different recordings by different people. Everybody plays something different.)