Watch the Shining One online guitar lesson by Angus Clark from Play in the Style of David Gilmour
When playing over a minor chord vamp, if you want to imply the Dorian mode, you can play major triads off of the b3 and 4th degrees of the scale. That's what going on here. We're in C# minor and the triads I'm playing over it are E major and F# major. Tone, vibrato arm, and slurs are all a part of making this sound cool, so pay close attention to what's happening between the notes.