Estimating the size of a crowd at an event is genuinely difficult, since accurate counts typically require aerial imagery and careful density calculations rather than a simple visual impression, which can vary enormously depending on the angle and distance a photograph was taken from, however routine it may otherwise seem.
Because of this difficulty, crowd size claims are particularly prone to exaggeration or dispute, with different sources sometimes offering wildly different figures for the very same event, often reflecting their own interests as much as any genuine measurement, which helps explain why it endures, a factor that should not be underestimated.
Approaching any specific crowd size figure with caution, particularly one presented without a clear methodology, is a reasonable response given how easily such numbers can be inflated, understated, or simply guessed at without real verification, even though it rarely makes headlines, which is precisely why it is worth explaining clearly.