(pause for trial.)
Well, that didn't work. Why? Because there is no "edit/copy/paste" function inside the dialog box. When I used the edit drop-down at the top of my browser toolbar, it didn't show "paste" as active. I can paste into this, the main posted message: http://pics.livejournal.com/e_moon60/gallery/00009084 but I can't paste into the dialog box.
I will now try method number two, trying to highlight the URL here, and then get it into the dialog box.
(pause for trial)
And that didn't work either. I highlighted the URL, touched the "link" icon, and got the dialog box which has no way to paste the highlighted URL into it. Just like before.
Allow me to mutter that this is a very...awkward approach to making links. What should happen is that anything which starts with a valid http:// either automatically functions as a link, or when you highlight something and touch the "make link" icon, it makes it a link.
The only way I see to make this gallery a link is to physically type in the entire URL into the dialog box, which is a) a nuisance and b) prone to typist error. I just did that. It seems to have worked, but...there's gotta be a better way.