The Splash Page was designed to be used as an image link to a full page gallery within an existing web page (alongside other content) in small screen devices where, if the gallery was displayed, it might be too small to be usable. The Splash Page can be thought of as a stepping stone to a full page gallery. (It was not designed to be used as a full browser page itself.) As such, there is no native support for a link back to the embedding page from the Splash Page. (The Splash Page would normally be on the embedding page.)
As the entire Splash Page is a link to expand the gallery, the only way I've been able to include a link in the Splash Page is by using an HTML <a> tag with an 'onclick' attribute and a JavaScript 'window.open' command in either the galleryTitle or galleryDescription (both of which are displayed on the Splash Page).
For example, you could use a galleryDescription such as:
This is a Gallery Description.<br>Click <a href="http://www.example.com/" onclick="window.open('http://www.example.com/', '_self'); return false;">here</a> to return to main page.
The Small Screen Mode's thumbnail page usually includes a 'Close Gallery' button (unless explicitly disabled) for the user to return to the embedding page (where the Splash Page usually is).
The only way to include a link in the Small Screen Mode's thumbnail page would be to use a link in a galleryTitle such as:
This is a Gallery Title.<br>Click <a href="http://www.example.com/">here</a> to return to main page.
More information about using HTML formatting in the galleryTitle can be found in this FAQ:
How do I add HTML formatting to the Gallery Title or Back Button?
...they may need to hit the back button several times, to get back to photos_test.php.
This is due to setting enableDirectLinks="TRUE". When enabling direct links, each image in the gallery is given a unique URL and when each image is viewed, a new entry in the browser history is created (meaning that if many images are viewed, the browser's back button will step back through each image). If you set enableDirectLinks="FALSE", then there will be only one browser history entry for the gallery page (rather than one browser history entry per image viewed).
I understand that different users have different requirements but I would normally recommend that you keep screenMode set to its default value of AUTO and allow Juicebox to display the gallery in Large Screen Mode in desktop browsers. You could maybe display more thumbnails per page (like in this demo gallery) and make use of either the Thumbnail Button (set showThumbsButton="TRUE") to toggle the thumbnails on and off or the auto-hide functionality (set autoHideThumbs="TRUE") to auto-hide the thumbnails after a specified inactivityTimeout.
You could also reduce the size of your thumbnails slightly (via thumbWidth and thumbHeight) so that more thumbnails can be seen on the page at once (before scrolling through thumbnail pages is necessary).
I realise that perhaps not all your thumbnails will initially be displayed in Large Screen Mode but, depending on the browser viewport (and the number of images in your gallery), there is no guarantee that all your thumbnails will initially be displayed in Small Screen Mode, either. (Multiple thumbnail pages may be required to display al your thumbnails.)
I hope these notes help (at least to clarify things).
Incidentally, please feel free to post suggestions for future versions in the Feature Requests forum thread.
This keeps all the ideas together and ensures that they are not overlooked by the developers.
Thank you.