Actually, while trying to clean out a copy of my config (get rid of password related things, irrelevant bloat from toolbars and other customizations) I figured out what's causing it.
Create a label filter like blueroly suggested here: Suggestion: show info for empty dirs in thumbnail view
...and you should be able to repro with the file I uploaded, in a library path. Same issue does not occur with the same file and path when viewed through the physical path.