[upofadown]

It wasn't clear to me from reading the article what the specific usability improvement is here. So you still have to compare the ridiculously long number once? With each and every device that anyone you want to message with owns? What does it mean if you don't?

It used to be relatively clear that you had to verify everyone and maintain that verification. This seems potentially more complicated...

[palata]

My understanding is that with this, your client can verify the key automatically. If you don't trust that verification, then you have to do the manual check.