Your picture is the crux of the whole matter. You say the earth is flat. And you back it up with a picture that shows some of the earth being flat. But the person in the picture isn't flat. And the mountains in the background aren't flat. And if you got down close to what looks like flat ice or water, you would find that it isn't flat either. So, where is the flat? Your picture is absolutely useless for showing flat earth, unless you describe how the picture shows flat earth.

In an Olympic size swimming pool, when the water is absolutely still, it looks flat. Not including adhesion or cohesion, or the height of the molecules of water, the water actually curves with the curvature of globe earth. The reason you can't see it is because the amount of curvature is so small that it can't be observed. However, in a swimming pool the size of the ocean, it is readily observable.

Since you are unwilling to recognize these simple truths, but you want to show pictures like the above, and then let people try to reason their way around what you mean... would you be a religious leader like Jim Jones (https://en.wikipedia.org/wiki/Jim_Jones) if your FE went far enough among people?