At first I Just Said No to the sign in overlay. Based on the comments here, the fact that it was a Mozilla project (I trust that brand, so it might help to say

At first I Just Said No to the sign in overlay. Based on the comments here, the fact that it was a Mozilla project (I trust that brand, so it might help to say 'Napkin by Mozilla (Labs)' or similar), and the fact that I actually wanted to try a real example of Persona, I logged in. The Persona experience was positive enough, but when I was bounced back to Napkin the examples under the overlay have disappeared. There is nothing to explore, just a blank interface; disappointing. This is wasting too much of people's time to qualify as an MVP and is wasting the project's opportunity to get some decent feedback from HN. How not to launch.