This exercise is from the Core Skills exercises on string Bends.

As well as bending single notes, it is possible to bend chords. This little tune is a simple, but effective example of bending chords during play.

Powerchords are the easiest type of chord to bend, so we use them here. Also, we add a harmony, also using bends, just for nice musical effect:

This is the main chord sequence: D5 - A5 - D5 - E5 (bend) - E5 (bend) - E5 (repeat)

Notice that we bend downwards (towards the floor). If you bend upwards here there is a risk of pushing up the Low E string and making it sound out. Also, the positioning of fingers for powerchords makes it more natural to pull downwards with the fingers when bending. It is easier.

While that guitar keeps playing, just for fun we add another guitar which plays a higher harmony (also shown in the ActionTab). A harmony is a combination of different chords that work nicely along with the chords played by the first guitar:

F#m - C#m - Bm - E major (bend) - E major (bend) - E major (repeat)

The trick is to ensure that each string is bent by the same amount. It takes a little practice, but isn't too bad. Here we bend around fret 7 where the strings are a little looser. Each chord is a 'half-bend' - i.e. bend up by 1 fret, and bring back down to starting position.