By default (using the regular embedding code), Juicebox will look for a file named 'config.xml' in the same directory as the page containing the gallery's embedding code. (Your gallery structure does not have a 'config.xml' file in this location.)

If you move or rename this file, then you can point towards it using a configUrl option in your embedding code.
When using a configUrl, all paths in the 'config.xml' file will still be relative to the embedding code page.

As you have uploaded an entire Juicebox gallery (your 'Juicebox' folder) to your web server, you can point towards this folder using a baseUrl option. Please see here for details.
When using a baseUrl, all paths in the 'config.xml' file will be relative to the baseUrl so there is no need to make any modifications to any gallery files.

Just change your gallery's embedding code to the following (add the baseUrl entry pointing towards the gallery folder) and all should be well.

<!--START JUICEBOX EMBED-->
<script src="/Juicebox/jbcore/juicebox.js"></script>
<script>
    new juicebox({
        baseUrl: "/Juicebox/",
        containerId: "juicebox-container",
        galleryWidth: "100%",
        galleryHeight: "100%",
        backgroundColor: "#222222"
    });
</script>
<div id="juicebox-container"></div>
<!--END JUICEBOX EMBED-->

Short descriptions of configUrl and baseUrl can be found in the Embed Options section of the Config Options page.

You're welcome!
I'm glad you've got it working.
Thank you for letting me know.

I guess it's a personal thing (organizing files on a web server) and there are certainly a number of different ways you could arrange things with the availability of the configUrl and baseUrl configuration options and the possibility of storing all your images in a single folder.

However, here's what I'd do.
I'd keep each gallery in a separate folder and embed the galleries using the baseUrl method (as you currently do for your 'Clay_School' gallery).
I find that this helps to keep things organized. You know exactly where all the files for each gallery are. There is no need to search through a single folder of images wondering which images are for which gallery.
Also, if you ever need to edit or update the gallery in the future, all you need to do is swap out the gallery folders (new for old).

I'd also have all galleries share a single instance of the 'jbcore' folder. Please see the Using an External jbcore Folder for details.
Basically, you'd just upload a single 'jbcore' folder for all your galleries to share.
For each gallery, you'd just point towards the shared 'jbcore' folder.
This has the advantage of being able to upgrade all the galleries on your web site at once (for example when a new version of Juicebox is released) by replacing just a single 'jbcore' folder on your server.
This means that the 'jbcore' folders in all your gallery folders are redundant. You can leave them in place if you want (they'll do no harm other than take up a bit of space) or delete them.

I hope this helps.