Through recent research into what makes content go viral, I found out that one of the best ways to get a landslide of 'Likes' and 'Comments' is to lead someone into a gallery of interesting pictures or videos that they start flipping through; 'commenting' and 'liking' as they go. This is a scenario that happens frequently on FB.
This made me immediately think of your plugin and how it would be a VIRAL POWERHOUSE if it could achieve the following FaceBook click flow:
1) FaceBook user clicks on a shared photo or video link.
2) They are taken to a Social GALLERY where the photo resides (which auto loads) and the gallery displays the photo they clicked on.
3) If they like what they see, they start flipping through the gallery's content, 'liking' and 'commenting' willy nilly.
4) Wash, rinse, repeat...
Obviously SG was designed to encourage viral activity, however, as the plugin functions now, the opportunity for this kind of 'gallery viral frenzy' via Facebook is squelched because a shared link on FaceBook currently only links to a single Social Gallery Image Page, with pretty much nowhere to go after that.
How To Do It?:
I don't think you'd have to change where shared FB links point to. You could just code the SG Image Pages so that when they are landed on, a SG lightbox auto-loads, which includes every image in the SG Image Library... and also code the pages or gallery so the default start image for the gallery is the image of the current page. This is the simplest way I could think of to achieve the click flow I described.
Of course there could be more complex solutions that would give us more control over what images are contained in the galleries for each specific Image Page. Like something similar to NextGen, in which we can manually build galleries that can be assign to specific SG Image Library images within the SG Image Library interface, via short code or pull-down menu.
...Or a different approach might be to integrate NextGen into the idea. I could see entering NextGen short code onto SG's Image Library on an Image by Image basis, but unfortunately the image presented would be each NextGen's default image, not the one the user clicked on. Not being a coder myself, I wouldn't know if this problem is solvable.
However, in the end, I would be PLENTY happy with my first, simpler implementation idea. Possibly it's simple enough to implement in SG Photo 3.0? However, if you can't squeeze it in, I'm just praying you will have time to integrate it into the next SG VIDEO Add-on update since my site primarily has video content. The simple version would at least give my FB originated visitors the chance to flip through the videos I include in my SG Video Library (YouTube friendly please) and encourage a single visitor to generate multiple "Shares", which will attract more visitors, re-shares, and around and around we go.
It really would add so much more viral value to SocialGallery!