A screenshot won't tell if the monitor uses PWM, a photo would be better. Alternatively, when you look at that line as it moves, do you see several lines as if there was some kind strobe effect? Or is it just a blurry, single line?
Another good way to tell whether a monitor has PWM is to shake your hand in front of the monitor, if you see some kind of strobe effect it's using PWM.
Edited by Pereb - 11/4/15 at 10:57pm