Most CNC/Rotary engravers penetrate into the metal itself and remove some of it and giving it a recessed area.
Most lasers only touch the surface of the metal, unless it's YAG laser that is hot enough to melt the metal itself and most don't get that hot.
Looks like your engraver did a great job. Another good choice for laser engraving is Jason @ Quentin Laser/Quentin Defense. He engraved a bunch of my NFA stuff. And all of my silencers.
Check out the first silencer I made that he engraved for me using a custom graphic of a screaming vampire (skull and spine) in the style of Iron Maiden's Eddie mascot.