Why arent we in the top of the search? Why only 2 pictures are shown?
Unfortunately, only Google can answer your questions with any authority. They are the only ones that know what algorithms they use to index and rank pages.
I notice that the pages ranked above yours in the search results include YouTube, Facebook and Twitter pages.
They are very large websites with a huge number of backlinks and, as such, they will probably always be ranked above your own website. Unfortunately, there is little that you can do to combat this when dealing with subject matter that crops up on popular websites and media sharing platforms.
The best you can do is provide information regarding your images in your web page (which is what the SEO Content Code generated by JuiceboxBuilder-Pro does) and follow Google's own guidelines and suggestions in their Search Engine Optimization Starter Guide: http://static.googleusercontent.com/med … -guide.pdf
Here's a one-page version: https://storage.googleapis.com/support- … 97B2C885BD
If you have not already done so, then I would recommend submitting your site to Google to be indexed via their Search Console: https://www.google.com/webmasters/tools/submit-url
If there are few (or no) links to your own web site from other web sites, then Google may not be able to find or index your site.
Another question is, that in the source code of the image gallery generated, we can see that the alt text doesnt show the original alt text, either it show the url.
I would think that Google are more likely to index your gallery pages based on the static HTML code on the page itself rather than the code generated dynamically by the 'juicebox.js' file. I would certainly think it is unlikely that Google would ignore the static HTML code in favor of the dynamically generated code (although, again, only Google would know this for sure).