Steven:
First of all, thank you for your prompt and thorough examination of the assorted files involved.
Second, alas, I still have this problem. Or at least, I seem to still have the problem. Here's what I did:
1) I removed the entire meta/viewport lines from my web server's gallery.html and index.html files, cleared the cache on my iPhone, opened the page in Safari... and got the same results as I described in my first post.
2) Next, note that I had been updating my galleries by replacing the jbcore directory for each gallery -- using a python script I described in http://juicebox.net/forum/viewtopic.php?id=147 -- as each new release of Juicebox Pro was released. That is, I hadn't actually been re-generating most galleries.
This time, however, I generated the http://www.billanddot.com/Emma-pictures/index.html gallery anew. That is, I ran jAlbum, with the Juicebox skin, with the Pro options. I had updated the Juicebox skin a few days ago in jAlbum, and then replaced the jbcore directory for that skin with the real (Juicebox Builder) jbcore.
So, in jAlbum, I did a Make Album and then Upload. After this process was completed, I looked at the new gallery.html and index.html files and, as you stated, there were no viewport lines in them.
So I cleared the cache again, went to that gallery, and got the same results as before.
BTW, to clear the cache on my iPhone, I go to Settings --> Safari --> Clear History and Website Data --> Clear History and Data --> (press). I think that's what I'm supposed to do, and it zaps any sites I may have had open in Safari.
Perhaps there is something I'm supposed to do to force cache-clearing on my server (hosting by Bluehost.com) that I don't know about.
Last, as you can see by the simple way I generate all of these standalone galleries, I have no interest in playing around with scalability, i.e., I just want to let Juicebox handle everything for me. So I haven't (yet) attempted to manually add code -- such as the optional lines you presented -- after jAlbum has generated a gallery for me.
Er, um, you have any other thoughts about this? It's really weird that only one of two very similar galleries exhibits this behavior.
Thanks,
Bill P.