TfL 360/2 360 205Southall Southall

Nice! Is it normal for there to be only one headlight illuminated, or is the driver’s side just burned out?

@ Maersk.146
I had my own thoughts on this question but hadn't looked up the reason. See here this was copied from a forum
"Headlights are there preliminary for track workers to see trains approaching and also reflecting off line-side boards not for the driver, trains have night and day lights (day light 2nd mans side- night drivers side) and marker lights (LED'S) most modern trains have cyclops lights, at the top/middle of the front. And to add most modern trains use halogen bulbs compared to filament bulbs ( that's why they are brighter) hope that helps."
Also you may of noticed that everything in the UK has a yellow front this was introduced years ago to give the track staff a sight on coming trains as lights were not fitted. However if you view my class 710 and 345 the yellow fronts are not deemed not necessary as the LED light is more effective. More info here https://www.railwaygazette.com/news/traction-rolling-stock/sing...html
So this EMU in its brand new livery, TfL decided they would still have the yellow front.

Sometimes drivers change the headlights to greet the photographer .

@bob.s @bfsSwiss Thanks, guys! In the US, they use all the lights they have, to better warn motorists at grade crossings and also track workers. We have a very litigious society, so woe be unto the engineer who forgets to turn back on his headlight and ditch lights after a meet and then hits a car at a crossing...