Magical Creatures
A major piece of the stage spectacle in Harry Potter and the Cursed Child is the physical manifestation of magical creatures from the franchise. Because the language is so spare and plot-focused, the play supplements with impossible feats of puppetry and stagecraft. The reader is meant to imagine these incredibly cinematic moments with hordes of Dementors, contrasted with moments of spoken references to Augeries, Phoenixes, and dragons.
Violence in the Alternative World
The alternative versions of time are filled with imagery of a world where Voldemort rules. References to "mudbloods" and "Blood balls" and "torture" are also juxtaposed with words like "valor" to create a sense that bravery equals violence in this version of the Wizarding World.
Food
There are many examples of food imagery in the play. This motif is perhaps the most enduring. Hermione speaks of Ron tasting of "fish sticks," and he tells her that she tastes of "toffee." The trolly witch's describes how pumpkin pasties become grenades (making food dangerous) and Ron takes a detour to the Hogwarts kitchens.
The Specter of Danger
In the dreams, we not only hear the specter of Voldemort, we see him rise from behind his parent's tombstone in a "jagged" and frightening omen of what's to come. The imagery of Voldemort is specifically vague, so when the audience finally sees Voldemort in his stage form after the suspense, it is ironic that it is Harry who is actually the thing we have learned to fear.
