@SteveClough @saltphoenix Gun shooting has more of a "gently squeeze" so the force of pulling the trigger doesn't move your aim, but you do have to be rigid enough that the kick doesn't send the gun flying towards your face. If there's a stock or heel then you have to be rigid enough so the force of the gun firing doesn't move your aim but loose enough so that your body can absorb the kick. Bows want to follow the arrow, guns violently explode away from the bullet. In my experience, anyway.
@mdstevens0612 Air pistols have basically no recoil. Holding it with two hands (or placing the gun on a support beam as is allowed in senior leagues over a certain age) significantly improves stability while shooting. But the Olympic discipline seen here requires a one-handed free-standing grip. It is totally normal to have the off-hand in a pocket or hooked into a belt to support tension in the body's core which improves overall stability and reduces sway. There is nothing special in his stance