Jongsu doesn't follow Haemi to confirm what she's doing — he follows her because following is now easier than not following.

The film stages this with meticulous routine: the binoculars, the notebook entries, the apartment vigil, which aren't dramatic gestures of passion but infrastructure.

And infrastructure, once built, generates its own justification. He has the tools, the tools require use, the use generates data, and the data generates certainty — not about Haemi, but about his right to look.

The film's actual insight arrives in the scene where Jongsu confronts Haemi about the man in the Mercedes. He has no proof, only surveillance, and she denies it — yet he doesn't need her confession because he needed the act of looking to feel legitimate. Lee understands this transaction perfectly: the apparatus doesn't need to be right, it needs to operate, and once it operates, the operator becomes its customer, then its prisoner.

By 2024, this apparatus is no longer exceptional — it's the default infrastructure of connection itself, offering every user the same toolset of location data, activity logs, social graph mapping, and algorithmic pattern recognition so that the stalking would be indistinguishable from normal use, the certainty would be free, and the fact that he might be completely wrong about Haemi would matter less than the fact that he could know, so he would look, so he would believe.