The small yellow arrows you can see on the platforms of some stations are not targets. They don't indicate where you can stand to get on the car more quickly. Quite the contrary! The yellow lines indicate the boundary zone to keep clear in order to allow the easy departure of passengers already in the car getting off at your station.

Keeping a low-congestion area allows people to empty off the car more quickly, allowing you to get on board just as quickly and smoothly!