What dramatic visual effect illustrates the importance of blocking the Earth's glow for an astronaut?

The difference in visual contrast for surrounding stars becomes immediate and dramatic

The immediate impact of blocking the Earth's reflected glare serves as a powerful, real-time demonstration of how proximity to a large, illuminated body fundamentally alters the perception of faint deep-sky objects, even in the vacuum of space. If an astronaut were to position their hand, or any object, to physically block the bright arc created by the sunlit Earth, the resulting change in the visual contrast of the surrounding stars and the Milky Way would be immediate and highly pronounced. This effect underscores that the suppression of faint objects is caused by overwhelming brightness contrast rather than intrinsic dimness of the celestial target itself.