The Man From Another Place tells Cooper that "when you see me again, it won't be me." Although attempts were made to get Michael J. Anderson to return to the role for the revival, the end result was that it wasn't him, and rather than recast the role, the character was mutated into an electric tree.
The singer in the Red Room is Jimmy Scott, a cabaret singer from the 1950s known for his high voice (due to a genetic disorder which halted puberty). Scott had been largely forgotten until he performed at songwriter Doc Pomus's funeral in March 1991. Scott's performance on Twin Peaks less than three months later contributed to his comeback.
Had BBC2 not put the show on a 3 week break for World Snooker coverage after Episode #2.15, this episode would have aired in the UK BEFORE the US due to their hiatus of the show allowing the UK to catch up. It ultimately went out one week later than the US on June 18th 1991.
The trivia items below may give away important plot points.
One of Laura Palmer's last lines: "I'll see you again in 25 years" refers to Cooper's dream in season one (in which Cooper is an old man) when Laura Palmer whispered the name of her killer into Cooper's ear. This understanding of the line is all but confirmed by the International version of the pilot. In this version, Cooper's dream begins with the subtitle: "25 years later." Also, the first episode of _"Twin Peaks" (2017)_ aired 26 years after this episode aired. This episode takes place in 1989, while that episode takes place somewhere between 2015 and 2017.
Romance between Cooper and Annie was added at the last minute to replace the one between him and Audrey. That may explain one extremely curious scene. Right before Nadine awakes from her amnesiac state Norma and Ed are oddly relaxed, seemingly unconcerned with Norma's sister having been kidnapped by a homicidal maniac.