The film is an uplifting story about a girl who wants to buy a pretty goldfish for the Iranian New Year, Nowruz. In the process, she has to go through difficulty after difficulty as everyone is simply too preoccupied for the festival's preparation.
Other than Cannes, the film is Iran's entry for Best Foreign Language Film in the 68th Academy Awards and made international news not because it won the award (it didn't) but because the jury refused to follow the Iranian government's attempt to withdraw it.
Examples of tropes included:
- Attention Deficit... Ooh, Shiny!: Razieh can't walk for a minute without focusing on something that she has never seen or is forbidden to see. Her curiousness actually is what causes her to lose the 500 toman bill. Justified, as she's still a child.
- Big Brother Instinct:
- Ali, who despite frequently calling Razieh troublesome contributes the most during their quest to get back her 500 toman bill. And the aforementioned bill is given to Razieh in the first place because Ali manages to convince their mother in lieu of buying him new shoes. Plus, when he fetches her after the bill is lost for the second time, there's no indication that their parents are responsible for tasking him, as he doesn't mention them; he could very well be genuinely worried that she doesn't return on time.
- The army man, as well, who offers Razieh help because she reminds him of his two younger sisters back home.
- Chekhov's Gunman: Every important character that would play a role much later can be spotted during the market scene at the start. In fact, the balloon seller who helps Razieh get the money interacts with Zahra a little bit, possibly to tell her where Razieh is.
- Cue the Rain: In the climax, when Ali tries to look for a chewing gum to stick the balloon, it starts to rain.
- Dramatic Irony: At the end, the owner of the shop where the bill fell down urges the Afghan Boy to come home. The boy simply sits and ponders. He doesn't know that the latter came from, well, Afghanistan, which in 1995 is currently mired in a civil war that would end with a nightmarish theocracy.
- Earn Your Happy Ending: Razieh does eventually manage to retrieve the bill and buy the goldfish, but it takes a considerable effort (mostly thanks to her brother) to do that.
- Fish out of Water: The army man hails from a close-knit community and now has to work in a metropolitan area where individuality persists.
- Humble Goal: Razieh just wants to have a pretty and fat goldfish for the New Year, that's all.
- The Namesake: The titular white balloon appears at the end, being used by Razieh, Ali, and the Afghan Boy to finally pull the 500 toman bill from the sewer.
- Never My Fault: Mr. Bakhtiari explodes at his customer, who wants him to shorten his shirt's neckline, saying that it's not his fault that the shirt is too loose, it's the customer's neck's fault.
- Nice Guy: The army man, who sincerely wants to help Razieh get the bill, even offering food and sharing stories about his family back home with her. Unfortunately, the way he does the talking (approaching her while the streets are empty) gives her a bad impression, though she calms down enough for her to wave him off when he leaves.
- No Antagonist: As the plot centers on the quest of a young girl to retrieve a bill that she accidentally loses, the film has no one that can be considered an antagonist.
- Real Time: The film starts roughly an hour and twenty minutes before Nowruz and ends just as the festival is about to commence, corresponding exactly to the film's running time of 83 minutes.
- Snake Charmer: Appears as a street artist wanting to acquire money for the New Year.
- The Voice: Razieh and Ali's father is merely heard ordering Ali to buy a shampoo early in the film.