dude first off,
Those are not clouds where it says Appalachian Mtns, which are 500 MILES away. Further, the horizon extends what appears to be another 500 miles. A thousand+ miles.
Then this picture which I assume you are talking about,
Those are mountains, not clouds. You can say they look like clouds, but the video in full context verifies that they are in fact the Rocky Mountains.
I know you are skeptical/devil's advocate right now, but there is far more than one example. The BIG PICTURE is that you can still see the ground from 1000+ of miles away. There is NO WAY POSSIBLE you can do that on a BALL first of all, because the curvature would block it and secondly, the horizon would appear further and further down the more you vertically ascend. AND REFRACTION WOULD NOT FLATTEN THE BALL! This is not even a close argument, the infrared footage OVERWHELMINGLY PROVES THE EARTH IS FLAT.