The screen brightness curves can of course be differently calibrated. But if Apple really wanted to show a fair comparison, they'd have just specified screen brightness in nits directly, instead of using this roundabout comparison.
Laptop screens can easily consume 3-7 Watts of power, which dwarfs the SOC power, and makes up for ~70-90% of the total system power draw for watching videos. So if the brightness settings were really different (in nits terms), this comparison is quite disingenuous on Apple's part.
You suspect they used a different screen brightness, but you don’t actually know.
It’s easily possible that the different laptops have a different number of clicks in their bightness settings since they use different panels.
I agree that it would be better for them to use a nits value or some other objective measure.
You however don’t know what the value is and so have made a false claim with your headline.
How about updating the headline to a question or a suspicion?
