And what a chord he appears to be playing!
He's doing a barre chord where the index finger is holding down all six strings. Back when I played guitar (mostly self taught) I could never do that - didn't have the finger strength. And it got harder as you moved down to the body of the guitar. In hunting down what that technique was called (because it's been a long time), I found a web site that has the exact chord Alex is playing. He's playing an E or an Eminor but because he's "barre-ing", it appears to be a B or Bminor if I'm counting my frets correctly.
http://www.fretjam.com/guitar-barre-chords.html
Go down to the photographs of the hands.