Complex sentence: The first flag was used only for the occasion of the signing of the Indo-Bhutan Treaty, and a modern reproduction of the flag (with several changes influenced by the modern flag) is displayed behind the throne in the National Assembly Hall in Thimphu.
Split into simpler sentences: The first flag was used only for the occasion of the signing of the Indo-Bhutan Treaty. Today, a modern reproduction of this historic original (with several changes influenced by the modern flag) is displayed behind the throne in the National Assembly Hall in Thimphu.