It's always hard to tell from a video, but are the strings on Brian May's guitar, set unusually low? They look like they're just a hair above the frets.
The same feeling in watching Jimmy Page riff on "Whole Lotta Love" in the "It Might Get Loud" documentary.
I love the look on Edge’s face when he was watching Jimmy play. Then watching Edge teach Jimmy play I Will Follow and questioning Edge....”are you sure about that?”.