What was it supposed to mean?

Elijah and Sierra walked back the way they took. He decided to walk her home before eight of the night. It was a sensible hour and he didn't want to break the rules, yet. As they arrived in front of her house, the lights out and the door shut close, he took out his cigarette and a lighter then he noticed how Sierra stared emptily at the house. He was curious about what she stared at so intently but couldn't find anything. The house was in complete darkness.

"If someone saw you like this, he would have assumed you live alone," the cigarette in his mouth attracted Sierra's attention from the house. "Your parents must work a lot."

"Not really! No! My father rarely comes home at night and my mother doesn't return at all, unless there is something important."

"So this is your everyday life!"