#8980 children are watching your [bad] manners
This girl has obvious observed adults well.* Here she is sitting in a priority seat and pretending not to notice an obvious candidate. "Let somebody else take care of it." is a Japanese motto—especially in politics and the bureaucracy.
Equal time: "Not my problem" is the American response—as I learned sitting at the front of a kneeling bus one rainy Los Angeles evening.
* I take that back. If she wants to qualify as an expert, she'd (a) spread her magazines and arms to occupy two seats or (b) feign sleep. The latter dates back, in my experience, to at least the Seventies.
• こどもは見てるよ(kodomo wa miteru yo) = "children are watching"
• 大人のマナー(otona no manā) = "adults' behavior"
• おとながお手本です(otona ga o-tehon) = "adults serve as examples"
• 優先席(yūsenseki) = "priority seat"
• 立っているのはつらい(tatte iru nowa tsurai) = "Standing is hard on me."
• 誰かがゆずるでしょ(dareka ga yuzuru desho) = "Oh, I'm sure someone [else] will give him a seat."