Pure side-delt isolation, locked in.
Push against the pads with your upper arms, keep your shoulders down away from your ears.
The machine lateral raise locks your arms into a fixed arc so the side delts lift the load without your traps, momentum or grip getting a vote. Pushing through pads on the upper arms rather than holding a weight in your hands removes the forearms from the equation entirely, which is why the burn lands so squarely on the caps of the shoulders. It's the smartest place to take lateral raises close to failure, because there's nothing to stabilise and nothing to drop.
It's more strict. The machine's fixed path stops you swinging and cheating, so the side delts do all the work, while dumbbells demand more control and stabilisation. Many lifters use the machine for hard, high-rep sets and keep free-weight raises for variety.
To shoulder height, upper arms roughly parallel to the floor. Cranking higher shifts tension to the traps and can pinch the shoulder, and the extra range buys you nothing for the delts.
Your shoulders are creeping up toward your ears as you fatigue. Set your seat height so the pads sit against your upper arms comfortably, then actively press your shoulders down before each rep.
