More and more people are watching entertainment on their phones. On a plane or on a train, or whatever, you see people with their headphones and they're looking at their iPhone or their Galaxy. You're reducing a medium that's meant to be seen on your 65-inch plasma screen at home for your 4-inch monitor on the train. People are ready to do either, and the content has to work on both.
You really have to bring your game and know what you want to do. And then, there are the producers and the writers and the director on the other side of the glass, and what they want. You have to be malleable to what's going to work, and you have to stay in the framework of the context.
Nine times out of ten, I'm trying to meet someone else's expectations, whether it's the director or the writer or the animator, when I go back in to re-record a line. I'm the icing on the cake, but the cake is the thing. I'm really just a hood ornament on a very solid vehicle.