As the sun gets lower in the sky it shines through denser layers of atmosphere. The thicker atmosphere's refractive properties have a prismatic effect on the Sun, allowing its image to be separated into its component colors. Meaning the sun's red wavelengths set first and the blue-green set last. The first image shows the red breaking away at the bottom.
Later as the solar disk was slipping below the horizon the green wavelengths of light were lingering above the Sun.