Question: What was the significance of showing us Lyla dropping her necklace outside the hotel? Louis didn't pick it up did he?
Question: Did August's dad know he had a son? And did August figure out who his parents were at the end and did he see them at the concert?
Answer: The answers, in order, are: "No", not initially but "yes" later; "Yes" and "yes." Their plan to meet the next day didn't work out, so August's parents ended up having a "one-night stand." When August's father - as well as his mother -heard the music that August was conducting, they were drawn to it like magnets. With his back turned against the spectators, August got the feeling that his parents were there. When he turned around to look, he saw his mother and father. The mother and father instantly knew that August was their son and August knew they were his parents.
Answer: I think it was a necklace she was given by her father, and it breaking shows that she is breaking away from him. Her father picks it up, not Louis.
If her father picks it up, how is Wizard wearing it later in film?