Jonathan Zachary’s review published on Letterboxd:
Finally rewatching this one year later, with a much closer eye on the protagonist, who in subtle ways is inexplicably off; rarely speaking, often totally nonrespondent. The mystery is not where the girl goes but what the hell is happening in the mind of Jong-su.
Ben is also a mystery, but whether he is responsible for Hae-mi's disappearance matters less than his total indifference to the less fortunate in general. Well-mannered though he is (and completely undeserving of what befalls him), he does not care to understand how his newly adopted friends navigate their lives. His associating with them is a simple amusement; around his affluent friends he seems bored to tears.
Ben's lack of sympathy comes through most clearly in the brilliant greenhouse conversation, where he conveys in abstract terms a disregard/disdain for what is common and unexceptional, albeit with his unwavering geniality that communicates, as a social elite, how untouchable he is.
Burning explores how mysterious the super-rich appear to ordinary people, leaving open the question as to whether suspicions of criminality are warranted, the film instead charges the upper-class with a dangerous indifference toward the rest of the world that, whether they deserve it or not, may eventually bring destruction.