Why Are New Short URLs Created Every Time You Tap "Copy URL"?

On iOS (iPhone), when you're using a shortener service, each time you select an uploaded file (in the "uploads" pane, with the thumbnails), tap on it, and select "Copy URL", it doesn't use the first shortener URL that was created the first time, but always creates a new one.

Was this intentional? If so, what's the thinking behind it?

It means that, on the back-end of the shortener service, you get multiple different short URLs for the same long URL, every time you just happen to copy the URL in Dropshare.

The shortener service back-end itself of course may create a new short URL for every request, since different users may want their own unique short URLs even if they're targeting the same long URL as others. But it seems unnecessary for there to be a new shortener every time you just copy the URL in Dropshare.

But perhaps I'm missing some logic.