This is simply a live-line roll cast (or forward spey) that is executed by raising your arms so that your had is ear level and then making the casting motion more down than forward with your arms while keeping the rod tip pointed at 1:00 o'clock. the cast ends by stopping the rod abruptly when your lower hand (if casting 2-hand rod) is level with your belt.
It is not a cast I would want to make all day long because of all the quick up and down arm motions; but it is a fairly powerful cast. A good single spey has it beat for casting efficiency and power though.