Hi,
Please explain how to use the adjectives "pleased" and "pleasing".
1. His conversation is very pleased/pleasing.
2. He had a pleasing/pleased look on his face.
Think of it in terms of 'which way the action is going'. eg
'a killing lion' is a lion that is killing something.
'a killed lion' is dead, it has been killed.
Thus, 'a pleasing look' is a look that pleases another person. 'A pleased look' shows the person who has it is satisfied/happy with himself.
It's the same for your first sentence, although it's a little more unusual to say a conversation is 'pleased'. I guess it shows that he is pleased with himself.
Best wishes, Clive