Answer:
When you look for similarites in two things you read ,you UNDERSTAND , NOTICE Them. example when you read the novels, you WILL ,CAN notice that the setting in the both is Colorado.
The metaphor in this statement is "the great millstone" it kind of qualification word it express how big the time was.
But in reality, millstone doesn't even have a relationship with the time.
So "the great millstone" is a metaphor.
It mean how are you but you can say how are you doing to and then u said good how are u