On https://jenkins.tails.boum.org/view/RM/job/test_Tails_ISO_experimental/67/
the screenshot shows that Evince did manage to open it, but the video lacks
the frames that prove it ⇒ I bet that Evince needed just a tiny bit more
than 10 seconds.

refs: #10776

refs: #10774

This might change in the future Greeter and also let's focus on actions
that people have to take (and not pretend to explain every thing here
which is not the point).