Two adjacent gray pixels (the star is between two pixels) won't have the same total brightness as a single fully bright one (the star is at the center of a sing

Two adjacent gray pixels (the star is between two pixels) won't have the same total brightness as a single fully bright one (the star is at the center of a single pixel) if the interpolation is not correct with respect to gamma. So, as the star moves slowly, I would expect some twinkling. This is probably the issue he is referring to.