Those are unhelpful, and incorrect diagrams. They give the impression that ground effect is something to do with the height of the wing from the ground being related to the chord, which it isn't.
Well I'm sorry you find them unhelpful, but incorrect they certainly are not. The pressure distributions are consistent with measurements on a wing of AR 5.0, so what basis have you for saying that is incorrect please? The streamline picture is meant to be consistent with the pressure diagram which, incidentally, relates to a point near midspan. Obviously it relates to a height far less than one would see in actual flight operations, but that does not make it wrong - it is an extreme case to demonstrate effects.
"Ground Effect" is noticeable when the height of the wing from the ground is less than the wingspan.
Sure, when you are flying airplanes that is when it starts to show up. But I certainly didn't say that ground effect depends on how many chords above the ground the wing is - that was your interpretation of the diagrams.
You can't show ground effect in a two-dimensional diagram, because it's inherently an effect that occurs only in three dimensions, like wingtip vortices.
There I'm afraid, you are just plain wrong - there is ample evidence that two dimensional wings exhibit ground effect characteristics.