Bringing owls to Athens means to do or undertake something redundant, pointless, or futile. I like idioms a lot. They are the perfect source of inspiration for cartoons. I this case it refers to the city of Athens in the time of Ancient Greece, where silver coins were minted with the image of an owl. Thus, to bring either owls or silver to Athens would be a useless venture.
Even if it is a very old Greek saying, it can be applied to a lot of situations nowadays.
