Document letter boxing in Tor Browser
For the release notes of 4.0, I created a screenshot but it would be worth mentioning it in the doc.
FWIW, I've spotted in the Tor Browser team meeting minutes that there's WIP aiming to improve the letterboxing; I don't remember exactly how; it could possibly make the resulting behaviour easier to understand by users. I don't know if that'll be enough to cancel the need for documentation.
Thanks for the pointer. The idea behind the doc is to explain the security benefits as much as it is to clear possible confusion.
Indeed Tor#32324 might duplicate this effort: https://trac.torproject.org/projects/tor/ticket/32324.