That's IT! LOL Look at EW...so understated, but you can tell what he's thinking. And Merry...now Carton, what is this Merry is doing? He's helping to focus the attention on what Pippin is saying. All his reactions are just helping to accentuate what Pip is saying. It probably has some professional name that you might know. But I love the whole scene. It only varies slightly from the book and when I read the part in the book, I can see them doing it just like this! LOL
That's what I meant,' said Pippin. `We hobbits ought to stick together, and we will. I shall go, unless they chain me up. There must be someone with intelligence in the party.' 'Then you certainly will not be chosen, Peregrin Took!' said Gandalf, looking in through the window, which was near the ground.
Then:
`You speak gravely,' said Elrond, `but I am in doubt. The Shire, I forebode, is not free now from peril; and these two I had thought to send back there as messengers, to do what they could, according to the fashion of their country, to warn the people of their danger. In any case, I judge that the younger of these two, Peregrin Took, should remain. My heart is against his going.' `Then, Master Elrond, you will have to lock me in prison, or send me home tied in a sack,' said Pippin. `For otherwise I shall follow the Company.'
Well... the professional name as I know it as is good acting. There must be some reaction to what Pippin said because it is funny... Merry has the strongest reaction because he is closest to Pippin and 2nd in the camera shot. EW must react because he is still in the shot... even if EW reacted as strongly as DM, it would have been okay because Pippin's statement demands the rest of the characters react. What I would love to see are the other shots that show the reactions of the other actors, and even those who are not in the scene.
Billy Boyd's comic timing is very good.