Adding a post and "creating" an updated post doesn't encode a link as a link, merely as text.
Example following in 30+ seconds if nobody posts.
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https://fbcdn-sphotos-g-a.akamaihd.n...53694490_n.jpg
That should be a click link, not copy/paste text, the url wrap isn't automatically added as normal.
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As an aside, quoting doesn't wrap it either, but editing your post does.