Why would it be difficult to see prominences if you were on the moon during a total lunar eclipse?

Answer 1

Because the Earth's shadow is much bigger than the solar disc appears, so the entire sun is blocked out, while on the Earth viewing a Solar Eclipse, the moon's disc is approximately the same size as the sun's.

Answer 2

During a total lunar eclipse, Earth blocks direct sunlight from reaching the Moon, darkening its surface. Prominences are bright, glowing gas loops on the Sun's surface that are not visible without the Sun's light. Since the Moon is in Earth's shadow during a lunar eclipse, there would be no direct sunlight to illuminate the prominences, making them difficult to see from the Moon.