You have seen a letter placed in a drawer. The character entering the room has not. The scene now contains two versions of the situation: the one available to the character and the one available to the audience.
Draw two small timelines
On one line, note when the audience receives a piece of information. On the other, note when the character receives it. Use only events the film actually shows or states. A suspicion belongs in a separate column.
The hidden letter is an invented example, but the exercise works with any clearly established information gap. It might involve a destination, an arrival or an object left behind.
Notice what you wait for
Once you know something the character does not, ask what you expect next. Are you waiting for discovery, worried about a mistaken choice, or watching to see whether your knowledge is incomplete?
A later scene may reveal that the audience also misunderstood. Keep your first inference distinct from the information explicitly supplied. The film can encourage an expectation without promising that it is correct.
Describe the gap precisely
Instead of “the scene is tense”, explain which piece of knowledge creates your anticipation and when it is resolved. You can then discuss tone with evidence rather than treating tension as a property of every similar arrangement.
Compare with offscreen space, where uncertainty concerns what lies beyond the frame. Both exercises ask how the film distributes information, but they begin from different viewing questions.