Steps to reproduce:
Visit this page from anonymous:
https://phabricator.wikimedia.org/vote/
What should happen:
You should see the list of Slowvote(s).
How to fix:
An Administrator should go here:
https://phabricator.wikimedia.org/applications/edit/PhabricatorSlowvoteApplication/
And change "Visible to:" from All Users (or whatever) to Public.
Blocking: