What do you think the absence of lights at the bar and on the pick-up truck might represent in this story?

I believe the absence of lights at the bar in Chapter One are meant to set the mood. It's dark in the bar, and Taylor can see the woman sitting in the back is frightened. A lack of lights makes this scene seem mysterious and secretive...... and it is in this secretive manner that Taylor is given and accepts the baby.

After reading through the first chapter, I see the reference to the lights on the truck. In Chapter One, we learn that just as Taylor is debating on whether or not to take the baby back into the bar and leave her there, the bar lights go out, the Budweiser sign goes out, and a pick-up truck leaves the lot. Her decision has been made for her.