The Ensign of Isaiah 11… What is it and what does it mean?

A Christadelphian Video:: Description: God in His wisdom took the problem of biting serpents and turned it into the solution. God told Moses to make a brass serpent and to put it upon a pole, an ensign or banner, and whoever looked upon it would live. In the same manner, God took His Son, the son of a human mother to declare the weakness of human flesh, to be the ensign or banner to draw both Jews and Gentiles unto Him.