Here we have the introduction of something we haven't seen before.
Longing is a difficult enough emotion to display using traditional animation. Quite often, animators fall back on the use of music to register longing. But, here, Pixar does it quite simply and effectively.
"Red's Dream" is about a small unicycle sitting in a dusty corner of a bicycle shop. He fantasizes. Not about being displayed properly, or being purchased by someone...
No, he dreams of being in the circus.
It is a simple, but powerful theme.
In one of my favorite movies, "His Girl Friday", much ballyhoo is made (comically) about the axiom "production for use". If you've seen the movie you know what I mean.…