There's a related phenomenon in astronomy called Eddington Bias. If you're doing a survey of stars in the sky, often times you are limited by the brightness of the stars, so there's some brightness below which you don't detect any stars.
Because photons arrive at your detector randomly, sometimes a few more photons arrive at the detector from a particular star than average, and sometimes fewer. One therefore sees small random fluctuations in the brightness of the star.
Because there are many more faint stars than bright stars, it is much more likely for a star just below your detection threshold to fluctuate up above your detection threshold than for a star just above your detection threshold to fluctuate down below your detection threshold. This ends up biasing the inferred median luminosity to higher values.
Because photons arrive at your detector randomly, sometimes a few more photons arrive at the detector from a particular star than average, and sometimes fewer. One therefore sees small random fluctuations in the brightness of the star.
Because there are many more faint stars than bright stars, it is much more likely for a star just below your detection threshold to fluctuate up above your detection threshold than for a star just above your detection threshold to fluctuate down below your detection threshold. This ends up biasing the inferred median luminosity to higher values.