This could very well be PEBKAC.
The module was installed, plupload installed, a new gallery created, a few photos batch uploaded, however we can not see any images, only links to the files. Did I miss a setting to render them as images and not links to files?
Here is what we see:
The way Views is configured:
FYI- We are using Storage API and hosting the images on S3- They all download fine, just no thumbs.