Final answer:
The provided texts do not mention a poster in Roy's bedroom or provide information about warnings regarding Siberian tigers.
Step-by-step explanation:
The question about whether the poster in Roy's bedroom warned about the dangers of approaching a Siberian tiger cannot be accurately answered from the provided texts. None of the excerpts mention Roy, a bedroom, or a poster warning about Siberian tigers.
The texts seem to be describing various scenarios, some of which pertain to dangerous or wild animals, such as a lion in a highly technologically advanced simulation room and tigers in historical Korean art, but they do not directly answer the question posed.