Why is there a door in front of Jesus feet in the painting 'the last supper'?

In Leonardo da vinci's "The Last Supper," the door at the front symbolizes the entrance to a new spiritual realm and the transition from the Old Covenant to the New Covenant established by Jesus. It also emphasizes the significance of the moment, highlighting that Jesus is the way to salvation. The door serves as a visual metaphor for the invitation to embrace faith and the transformative journey ahead for his followers.