Board Thread:The Panopticon/@comment-6032121-20190917111635/@comment-6032121-20191003231929

Friend from the Future isn't really a trailer, though — and inasmuch as it is one, it is a trailer of the "footage from a future episode, some of which is edited differently in the final product" variety. Personally I wouldn't have minded a valid FftF, but it's a whole other, and very thorny, kettle of fish. (…Sorry about the mixed metaphor there, those must be some damn creepy fish.)

Also, famous and amazing though 50 Years may be, it is by no means a story, it's just a bunch of flashy images of Doctor Who’s history strung together. And you're right, neither are any of the CGI Big Finish trailers I've laid eyes upon, which likewise show you some pretty images but don't try to make them cohere into in-universe narratives.