The student pilot reported that the flight instructor was attempting to demonstrate a soft-field takeoff with 10° of flaps after having completed a short field landing. The flight instructor had the student pilot “follow along on the controls” during the demonstration. After takeoff and while in ground effect, the stall warning horn sounded, and the airplane drifted to the right. Unable to gain airspeed by pitching the nose down due to their low altitude, the flight instructor instructed the student pilot to retract the flaps to 0°. The student pilot reported that immediately following the flap retraction, the airplane stalled to the left and impacted terrain. The airplane sustained substantial damage to left elevator. The student pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.