Sandbox (Symbol)
The sandbox is where Grandma is placed and where she dies in the play. It is a symbol of the fact that Mommy and Daddy treat her like a child, rather than a wise elder worthy of respect. It is a juvenile and undignified place for Grandma to die. It also symbolizes the bridge between life and death on a broader level. It represents the fact that death is a kind of return: to youth, helplessness, etc. Depending on how one interprets it, the sandbox can be seen to symbolize either Grandma's mistreatment or the reality of death.
"Hi!" (Motif)
Throughout the play, the Young Man barely speaks except to say "Hi!" with the same enthusiastic but vacant smile, every time someone acknowledges his presence. He is a vapid character, who does not have thoughts of his own, and instead embraces his physical nature. His excitable "Hi!" represents his empty-headedness and blankness, the fact that his identity is completely projected onto him—by society, by the characters, and by the audience.
The play itself (Allegory)
The whole play functions as something of an allegory, representing the psychic world centered around family, loss, grief, and death. The strange dream space to which Mommy and Daddy bring Grandma is somewhere between reality and unreality, a strange beach that is also a sandbox that is also a funeral that is also a gateway to the afterlife. Mommy and Daddy's response to Grandma's death is somewhat ambivalent, and the emotion beneath Mommy's experience is quickly covered over with a repressed sense of social propriety. Her line, "It pays to do things well," suggests that she is concerned with the superficialities of a well-done funeral, rather than the meaningfulness of grief or a real confrontation with death and existence.
The Young Man (Symbol)
The Young Man, as the stage directions and the script tells us, represents the Angel of Death. He seems like an unlikely candidate for a grim reaper, but he plays his part dutifully. His symbolic significance is left somewhat ambiguous and he seems to represent both death, as well as youth and vitality, as represented by his strapping good looks, physique, and penchant for calisthenics. Thus, there is a tension between the fact that he is such a specimen of health and vitality while also explicitly representing the harbinger of Grandma's death.
Rumble (Symbol)
Mommy hears a rumble off-stage after the lights go down. As she tells us, the noise symbolizes Grandma's imminent death. It signifies to Mommy that Grandma doesn't have much time left.
