I'm not sure how relevant this is to Juicebox but I appreciate you taking the time to point this out and I have notified the developers of your post above. Thank you.
It is true that metadata is not retained when JuiceboxBuilder resizes images but the loss of metadata is happening within a desktop application on the user's computer (rather than via the upload functionality of an online service) and then the files are being uploaded to the user's own web space. (We do not host any user galleries or sites at all.) I guess it's not for me to say how similar (or different) the two scenarios are.
Incidentally, I've just uploaded a test image (with EXIF and IPTC data) to a Showkase v1.6.1 site's Library and the image's metadata was retained after Showkase had resized the image. It looks like issue affects only JuiceboxBuilder.
As I mentioned earlier, it's not that JuiceboxBuilder is intentionally going out of its way to strip metadata from images, it's just that when an image is resized, the metadata would have to be read and stored somewhere before resizing and then written back to the new image after resizing. I do not know if the Adobe AIR API (which JuiceboxBuilder uses) has any methods available that could be used to make this possible. (I expect there would need to be different metadata read and write functions for different file types.)
I realise that, from a user's perspective, the issue is simply that metadata is not retained and the reason why this happens is not important but giving a little background information may at least help in understanding the problem.
Adobe seem to have been slow in implementing this in Muse (see this forum thread) and I do not know if AIR applications are still lagging behind. However, I'm sure the developers will investigate further.
Thanks, again.