The painting with the "rabbit ears" added is "A likeness of Moses", by José de Ribera (1638).
Easter egg: The professor uses a "Cony" brand TV. "Coney" is another name for the European rabbit.
The beginning of the lodge scene is a parody of a scene from the movie Peggy Sue Got Married (1986).
In reality Easter is a holiday that is a mixture of Christian and pagan traditions, much like Christmas. When the Holy Roman Empire came to power in Europe around 800 AD the Pope set out to convert people away from their native pagan religions and turn them to Christianity, to help make the transition new holidays were created that retained some pagan traditions. So the Christian tradition of celebrating Christ's resurrection was combined with the pagan fertility and renewal traditions that celebrated the start of spring. In pagan religions rabbits are seen as symbols of rebirth and resurrection and their ability to reproduce quickly can represent fertility and new life. The tradition of decorating eggs originates from the Christian holiday of Lent, which was a period of fasting where no meat or dairy products were eaten. The fast also often included not eating eggs, around the time of Easter many people found themselves with an abundance of eggs, so they were saved and decorated as gifts for children when Lent ended.