Poppins' bunny toy, which he made himself, symbolizes his passion… as well as the concept of passion in general.
What do you like to do more than anything else? What job would you like? Do you want to farm ferrets in France, or dance the tango in Toronto? Whatever you dream in your daring-est dreams, this toy bunny is that dream made real.
Does that seem like a lot of weight to put on a bunny toy?
Well... we might agree with you there. Is the bunny toy so great, after all? Isn't it just kind of a piece of useless kitschy junk? Everyone stares at it in wonder, and it's supposed to symbolize those vast, worthless dreams—the opposite of Poppins' boring job. "I'm a lily," Poppins yells. But the thing he makes as a lily seems like it could come out of a not-very-adventurous toy store.
But you know what else is a kitschy crowd-pleasing work of pure love that somehow also seems like a boring commercial endeavor? You Can't Take It With You.
Capra's film trumpets the joy of idiosyncrasy and following your heart out of the boring accountant job and into an exciting life of adventure and making bunnies. But the movie itself is not especially daring or dangerous; it's a feel-good Hollywood entertainment where the guy gets the girl and everyone turns out to be nice deep down.
The bunny, ears and all, is a symbol of the creativity in each and every one of you. But it's also a sign that that creativity needs to be kept within certain limits. Capra endorses feel-good, Hollywood-sanctioned bunnies… if he came face to face with the bunny from, say, Donnie Darko, he would probably run the other way.