You dumb ass. Here is an obvious way out of proportion example of how we see the horizon on a globe.
Say you were on top of a building that is higher than the ISS orbit and looked down towards the horizon it would look similar to this illustration.
Where everything that is below the curve or the tangent of the line of sight, would appear to be cut off bottom first just like the photo of the boat.
What the Flatties did to trick you was a strawman the normal people's explanation with that bogus photo fooling you into thinking this is our claim.
And yes, you were dumb enough to fall for it, again. Beyond sad!