"Luminous Light"
The Dong has a conspicuous nose that emits luminous light. The Dong was inspired to invent the light after losing the Jumbly Girl. He thought having an extremely bright nose would help him find the girl. However, the light does not help him to achieve his goal. Therefore, the luminous light symbolizes empty hopes. Having a luminous nose does not bring the girl back into the Dong's life. Even though the light stands out in darkness, it cannot extinguish the darkness in the Dong's heart.
Darkness
The luminous nose distinguishes the Dong when he is in darkness. He likes roaming at night instead of resting. The hope of finding the Jumbly Girl motivates the Dong to roam through dark nights. Accordingly, the darkness symbolizes the Dong's solitude and unhappiness, both of which can be cured by the Jumbly Girl's appearance. The Dong's futile attempt to hold onto a lost and unlikely love is comparable to living in great darkness.
Sieve
When Jumblies want to move from one location to another, they sail using a sieve. Ordinary sieves cannot function like boats when in water because they have holes that would allow water to pass through. Consequently, the Jumblies would drown before they get to their destination. Thus, the sieve symbolizes futility. The Dong's hope that the Jumbly Girl will arrive in a sieve is a delusion that encourages him to live in denial instead of getting over the Jumbly Girl.
