I have often thought this about Pippin's expression at this moment, and I have now found someone on Tumblr who agrees with me:
Merry: confused awe
Frodo: confused awe
Sam: confused awe
Pippin: Finally, I'm getting the respect I deserve from these peasants.
I mean, seriously. Look at Pippin's face. He looks so pleased with himself. (Now, if he had really killed a troll single-handedly as he did in the book, that would be something to be proud of...)
Fun fact: Pippin's father is the Thain, who is basically the de facto military leader of the Shire (if they have a Shiremoot) and the representative of the King (that would now be Aragorn) therein. When the Gondorians call Pippin 'the prince of the halflings', they're actually not too far off the mark.
Seriously, though... Pippin, don't let this go to your head. You're bad enough as it is. XD
In Pace Christi,