I see the NASA earth pics as what would fill your field of view from different altitudes. From a low orbit, you would only see a part of a continent, but be able to see more from half way to the moon (The real one, not your just-out-of-reach CD or whatever.) Experiment: Take a photo of a globe from far away and from very close up (wide angle lens to fit it in), then resize the pictures to make the globes in the pictures the same diameter.
You misunderstood me... I don't believe the canal is higher in the middle; Your original video makes the claim that water would be uphill in the middle it is if the earth is a ball, along with railway lines. It's the same erroneous point about having to point about having to point the airplane nose down to keep it level. Airplanes fly straight- and-level over the globe due to gravity.