Never mind.  SOLVED
I know that rotation of images is a minefield with inconsistencies throughout various software programs.  I've read up on it and thought I had a workflow that would deal with it.  But not completely it appears. 

I have been creating juicebox galleries and uploading to a Drupal 8 site. 

try, fkelly.org where you should see a menu of the Galleries I've done. 

I manage my image files with a variety of tools including Photoshop, Picasa, Windows file explorer and something called xnconvert when there is no other way to fix metadata.  Sometimes Picasa shows a file in portrait orientation but then has the thumbnail in landscape, if I can use those terms loosely.  It will show that the file is rotated 90 degrees under its properties.  In photoshop the same file, under file info will have metadata showing an orientation value of 1.  I've found that having files like this is a recipe for madness in trying to publish them to a juiceboxgallery.  For problematic files what I do is run them through xnconvert and strip out the metadata.  Usually this works.  Even Picasa can then deal with the files and prepare a proper thumbnail. 

But sometimes the madness is not resolved.  To see what I mean go into my gallery:

fkelly.org ... then select the Melbourne gallery.  Turn off autoplay and scroll through until you get to file:
20131023_142325.jpg 
It's file 109 of 127. 
In the gallery it shows "landscape". 

When I look at the same file in Cpanel it shows portrait:  in both the images and images/large directories.

a direct url to see the file is:

http://fkelly.org/drupal8/jboxgalleries … 142325.jpg 

even there it is "portrait". 

The section of the xml file that references it is:

image imageURL="images/20131023_142325.jpg"
    thumbURL="thumbs/20131023_142325.jpg"
    linkURL="images/large/20131023_142325.jpg"
    linkTarget="_blank"
    sourcePath="D:\Pictures\Australia melbourne\20131023_142325.jpg"
    largeImageURL="images/large/20131023_142325.jpg"

I left out the opening and closing brackets just in case.

When I view the file in Picasa, or Photoshop or even in Juiceboxbuilder, it's fine.  I have stripped out the metadata ahead of time so there is no orientation field.  I have confirmed this.  I've cleared Firefox's cache.  I've cleared Drupal's cache.  I've deleted the whole directory using my FTP client then reloaded it after confirming the juiceboxbuilder had rebuilt it the gallery with the latest info.  No joy.  I even looked at the Gallery in Internet Explorer with the same results.  And there are several other files doing the same thing to me or I'd probably just delete it and forget it. 

Any ideas?

Never mind.  SOLVED
I had originally embedded the gallery in a content item in Drupal using directory X.  It was one of the first I did.  Then I switched to a new workflow and set of locations for the galleries.  So, I was putting the revised Galleries in directory Y.  No wonder I didn't see any changes.  Changed the content item and all is good.  Rotation is still a P.I.T.A. but it ain't your doing.

Happy new years.