There are multiple things to consider here. If it’s on a different machine, then no. If it’s reflecting off my machine’s backglass, then yes. Headlamps are also not static lights, they move around as the player moves around and that movement alone can cause a distraction. Note that “distraction” here doesn’t mean that the light is too bright or something like that, it’s the fact that it exists and causes the brain to stop to process it for a split-second, and that could mean the player losing control and draining.
At our league, we typically have a few banks of overhead lights always on, but sometimes people bump the switch and turn them off. This almost always results in every active player calling out “hey, don’t mess with the lights!” Any non-normal change in lighting while playing is usually noticed pretty quickly.
To put this another way, would you be ok if I stood over your shoulder with a Maglite, and pointed it at the backglass/playfield and waved it around while you were playing? I would suspect not.
Josh is right here though, if it’s not reported then a TD can’t really address it. Best plan for anything really is to bring it up if you think it’s a problem, because not everyone has the same thresholds for what is and isn’t distracting.