This is a beautiful image and I think you for sharing it. I have not been lucky enough to see a sun set quite so dramatic with my own eyes, but it seems to be quite a humbling experience.

I do not, however, think that it necessarily shows curvature.

This is the working model of the flat Earth that I have come to know.

This implies that the sun disappears over the horizon not because it drops physically below it per se, but because of perspective. I had a problem with this at first, because I initially thought that this should mean that the Sun should get smaller before it disappears.

The problem is, I came across a video which speaks of how excessive humidity in the air can change this. Water molecules dilate the light source in the distance making it appear much larger than it is, which is something I have since paid close attention to and noticed to be factual.

This is the best example I could find to demonstrate what I mean, but perhaps the Sun does not get smaller on a humid day because the moisture in the air is dilating the light?

It seems there is at least two answers, both scientific, for just about everything. This is probably why after centuries, the flat Earth theory has still not died.