The physiology paragraph says ostriches “use their neck to hide within the sand”. Put that premise aside for a second and look at the job assigned to each neck. One long neck supposedly gets the animal down into cover. The other is explained as a way of reaching up.
Whenever I ask why a giraffe needs that much neck, I get told that long necks exist in nature. Fine. Why does the comparison stop just before the behavior?

−+Collapse or expand reply by nailbrush
A similar part does not require identical behavior. You would have to say which feature makes hiding a necessary use of the neck.
−+Collapse or expand reply by flatlander
Then pointing at another long-necked animal does not explain this one. It just makes the silhouette feel less exceptional.
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−+Collapse or expand reply by mothproof
There is another jump here. A neck being capable of a movement and an animal using that movement to hide are separate claims. Which one is the alleged omission?
−+Collapse or expand reply by flatlander
The behavior. The paragraph says the fabrication neglected it. I am not asking somebody to find a hinge in the photograph.
−+Collapse or expand reply by cansleeve
That is why I find this objection stronger as a question about the explanation than as a test you could apply to a single picture. A picture can show a neck. It cannot show what somebody forgot to design.
−+Collapse or expand reply by mudlark
I am not conceding the ostrich premise yet. The picture and the sentence are being treated as though they establish the same thing.
−+Collapse or expand reply by windowseat
the picture makes the giraffe look like the version that forgot to crouch. i would like to see the two animals compared at ground level instead of both posed upright.