A film emerges from a festival with extraordinary reactions and then meets a shrug on release. The gap is produced by who was in the room and what they were permitted to say.
The room selects itself
Festival and premiere audiences chose to be there, often queued for hours, and in many cases travelled for the occasion.
People who have invested that much are predisposed to enjoyment before anything starts, and the investment is not recoverable by disliking the film.
A general audience arrives having made no such commitment, which removes the effect entirely.
Festival programming compounds it. A film selected for a competition slot has already been filtered by people whose taste the attending audience tends to share.
The room amplifies itself
Reactions in a full auditorium are social. Applause begins because someone begins it, and standing follows because standing is visible.
Filmmakers and cast are frequently present, which makes an ovation a courtesy as much as a verdict.
Durations of ovations became a reported metric, which turned a social ritual into a number that appears to measure quality and does not.
Nobody in such a room can leave during the applause without being seen to leave, so the measurement records how long the least comfortable person waited rather than how much anyone enjoyed the film.
The terms of early reaction are restricted
Distributors often permit short social reactions before the full review embargo lifts, and those permissions come with conditions.
A format that allows a sentence favours enthusiasm, because reservations need explanation and praise does not.
Anyone hoping for continued access has an incentive to say nothing rather than something negative, so the early sample is filtered before it is read.
Expectations invert on release
Strong early reactions raise expectations, and the general audience meets the film through that raised frame.
The same film that impressed a room expecting nothing disappoints a public expecting a landmark.
Early enthusiasm can therefore actively damage the reception it was intended to build, particularly for modest, well-made work.
The gap widens with delay. A film praised at a festival may not reach cinemas for the better part of a year, by which point the reported reaction is all most people have retained about it.
What early reaction does predict
Festival response is a reasonable indicator of two things: whether a distributor will acquire the film, and whether it will feature in awards conversations.
Both are decided by roughly the population that was in the room, so the sample matches the question.
It predicts commercial performance poorly, because the audience that determines that was never sampled at all.