why is willy annoyed at Biff?How does he describe Biff?What does this tell us about Willy?

Willy is annoyed that Biff is not putting his talent, looks and personality, to use to make money. He describes Biff as lazy then just a few sentences later says that one thing about Biff is that he is not lazy. We learn about Willy's slipping grasp of reality, as he will continuously mix the past with the present. It lets us know that Willy is living vicariously through his sons. He did not achieve his own goals and he hopes that his sons will use the values that he holds dear and has instilled in them to become successful, thus validating his own superficial views on life and success.