Shylock was in a happy mood in the trial scene. he was happy because his bond was going to be fulfilled by the court. his revenge was going to be taken from Antonio. As it was all mentioned in the bond. Shylock was wanting only a pound from Antonio body. He was thinking that Antonio should not return back his money but he would get a chance of getting all his revenge.
Shylock was triumphant and elated during the initial part of the trial scene as he was sure that he would finally take his revenge on antonio by cutting off a pound of his flesh.
he was very confident that he would emerge as the winner. he had said in an earlier scene, "cursed be my tribe if i forgive him". there was a certain air of victory and triumph about him.