Rich media seem to follow cookies
At some point all youtube links on sgsgb started generating previews in russian (if available for that video).
Server located in Finland and trying to curl
the video gives me english result. Adding &hl=en
also gives english result.
I was unable to decypher HTTPS traffic but at least Pleroma does follow redirects (for http -> https links) and the fact that curl
from same host gives me one result but pleroma fetching gives another I'm led to believe cookies are at play.