So how is the 5th picture "obviously distorted", yet Felix and the capsule aren't?
It's hard to tell for Felix (and he is near the center of the frame, where there'd be the least distortion), but the capsule does actually look pretty distorted. As a quick test, place a straight edge of some kind against the right side of the capsule, and you'll see it's not straight even though it should be. If you do this for some other edges you might even be able to produce a crude correction for the image..
Surely no one who believes in the standard dimensions for the earth would think that so much curvature should be visible in that picture. Not from such a meager height. If that much curvature were actually visible without distortion you'd be looking at a major part of the earth, and major continents would easily be recognizable.