Antimatter thrust engine would be somewhat like a chemical or nuclear thrust engine, but with the difference that the exhaust would be pure light, and the fuel would the lightest possible fuel currently known to theoretically exist. That is known, but what would it really be like, meaning like how would humans perceive it? What would be an artistic expression of an antimatter thrust engine that would get reasonable close to a real thing? One way to create an effect of an antimatter thrust engine would be to place some led lights at the bottom of some flying saucer, make the flying saucer hang from some wires, shoot it with camera, and finally remove the wires with CGI. The led lights at the bottom of the flying saucer might create an effect that would be similar to a real antimatter engine. Would the pleasant glow of the led lights be realistic? Perhaps a real antimatter thrust engine wouldn't be so nice after all? Maybe real antimatter thrust engines would be like super weapons that melt kilometer deep narrow holes into the ground and blind all those humans who are too close to see the engine at action? How could you know?