This graffiti definitely accomplished the objective! Not only did I look, I got off the train at the next station and walked to the very end of the platform to take a picture.
As you can see the spray paint is on the side of one building’s wall, and above the roof of the Corner Bakery restaurant. Other than the offices in the buildings nearby, the graffiti is only visible from the El, and perhaps that was what the artist wanted. A thought out and targeted location.
I wonder, why paint the bottom 1/3rd of the letters yellow? Was the artist short on white paint? Is it supposed to look like the letters are filling up with something?