Thank you for your reply. I have to admit that I was paying attention to the sky, rather than the surface. The effect I am referring to can be seen in the transition from the 0:05 and 0:06 time in the video, and I see that what I perceive as a brightening of the sky is also accompanied by a brightening of the nearest structure. If I am not mistaken, the sun is already below the horizon during this sequence.

Of course, if this is just a delusion on my part, what I have written will make no sense to you!