Here's a billboard in Quebec for the Quebec City Magic Festival:
To show a "magic trick" via outdoor, this ad featured the quintessential top hat used by magicians. As pedestrians walked by, it would seem like birds were flying out of the top hat. Being a magical festival, they don't "reveal their secrets," but I assume their secret trick is bird seed.
I really like the concept of this outdoor ad, but I think it would have been even more of a spectacle if the part of the billboard that said "Festival de Magie de Quebec" was smaller so they could have had a larger top hat. More birds could feast on the seed, and would have been more dramatic if a whole flock of birds flew out.