Some AMOLED phones don't use PWM (usually 240 Hz) above certain brightness levels. Finding current gen devices is a different story.
However, even when they don't use PWM, they do flicker a little in the frequency of the screen's refresh rate (60 Hz, 120 Hz, ...). I think this is due to the scanline that updates the screen, and its amplitude height varies with models.
While to some extent I can get used to that smaller refresh rate flicker, I can't get used to the PWM. Red, strained eyes quickly each and every time.
The problem would be simple if the only thing to worry about was PWM. But there are other factors that can cause eye strain, too. Plus it frequently happens that reviews like the ones you got the pictures from only show one side of the brightness range (the PWM screenshot) and not the other one, where there may still be some flicker, just the author, perhaps as a result of him not knowing how sensitive users can be, decided it was not worth to be mentioned.