Just double-checked and the folder definitely isn't marked as private.
I just did some testing and confirmed:
- if I switch my account's view to multi-line format, the anonymous viewer can't see the details (they click on the right-triangle, it turns into a down triangle, but the Note doesn't display)
- if I switch my account's view to Grid format, the anonymous viewer can click on the "note" icon and see the Note.
Looks like a bug to me. How do I submit a proper bug report, rather than a forum posting?