If others are on display, you may feel as though these people need to be confined or that they draw too much attention to themselves. If you are on display, you may feel that your life is somehow abnormal and on display for others to observe and critique.
Do you feel as though others keep you on-display or caged-in? Perhaps you are uncomfortable with a particular sense of notoriety you have attained.
Still, a dream that takes place in a zoo may have to do with ecological concerns, memories of childhood or a sense of adventure.