I have used this trophy serve trying to correct a glitch in my serve. I actually didnt do well the serve trophy position - the elbow would always be too close to the body.
This trophy serve can be used as a progression when teaching or to break the serve apart to isolate a specific problem. Some pros on the ATP and WTA serve like this.
-- Volkl Catapult V1
-- Vantage Custom, 95, 340g strung, 63 RA.