Star Trek: Discovery season 2 adds an intriguing new context to explain the painting hanging in Spock's (Leonard Nimoy) quarters in Star Trek VI: The Undiscovered Country. The second season of the CBS All-Access series introduced a younger version of Spock (Ethan Peck) who teamed with his adopted sister, Michael Burnham (Sonqua Martin-Green), in 2257 to stop a sentient rogue A.I. called Control from destroying the galaxy and this experience had a profound impact on the Vulcan Starfleet Officer.
Star Trek: Discovery season 2 ended with Michael becoming the time-traveling Red Angel and leading the U.S.S. Discovery into the 32nd century. This was the culmination of a series of traumatic events for Lieutenant Spock, who was the Science Officer aboard Captain Christopher Pike's (Anson Mount) Starship Enterprise at that point in his career. This final adventure with Michael saw Spock escape from an insane asylum after his brain was damaged by a mind-meld with the Red Angel; at that time, it was Michael's birth mother Dr. Gabrielle Burnham (Sonja Sohn) who wore the time-traveler's suit and was trying to leave clues for Michael to stop Control. Spock and Burnham's battle to save the galaxy also healed their relationship, which was estranged after Michael pushed Spock away during their childhood. However, Michael and Spock parted ways when she jumped to the future and they never saw each other again.
Set in 2293, Star Trek VI: The Undiscovered Country takes place 36 years after the events of Star Trek: Discovery season 2. In the final movie starring the cast of Star Trek: The Original Series, Captain James T. Kirk (William Shatner) and the crew of the Enterprise initiated peace talks with the Klingon High Chancellor Gorkon (David Warner). Prior to the tragic events that led to Gorkon's assassination, which was part of a plot to prevent galactic peace that Kirk's crew ultimately foiled, Spock was joined in his quarters by his Vulcan protege, Valeris (Kim Cattrall). She didn't understand the painting prominently displayed in Spock's quarters, which is of Adam and Eve's banishment from the Garden of Eden. The wise, older Vulcan explained that it was "a depiction from ancient Earth mythology: the Expulsion from Paradise." As for why he displays it in his quarters, Spock said, "It is a reminder to me that all things end."
In the context of Star Trek VI, Spock's rationale for the painting, which is titled "Adam and Eve Expelled from Paradise" and was painted by Marc Chagall in 1961, made sense since it was the final voyage of the TOS crew and the definitive ending to their adventures together. However, it was always a bit strange that the Vulcan would hang a painting of a Biblical scene on his wall, and of Adam and Eve, no less. Spock is half-human but he was never religious; indeed, he regards Christianity as "ancient Earth mythology".
But factor in Star Trek: Discovery's retcon of Spock's life and suddenly, there's a fascinating new context illuminating why the Vulcan is invested in a depiction of the "Expulsion from Paradise": the angel in the painting could represent his sister Michael, the Red Angel, who was expelled from the 23rd-century along with her starship and crew in order to save the galaxy. Saying goodbye to Michael after years of being estranged and just after they finally reconciled was extremely difficult for Spock. Further, as part of his pact to protect his sister and the crew of the Discovery, Spock redacted all records of Michael and the Discovery from Starfleet records. Indeed, Spock never spoke of Michael Burnham again but he would want to remember her in his own way.
Ironically, almost a century later, Spock himself would be expelled from his own timeline; as seen in J.J. Abrams' Star Trek movie, the Vulcan was thrown back in time when he tried to stop the Romulan sun from going supernova in 2387. Ambassador Spock not only ended up back in 2258 but he was also stuck in the alternate Kelvin timeline as well, which is where the Vulcan ultimately died in 2263. Spock's time travel sent him in the opposite direction from his sister Michael Burnham, but, given the full scope of the Vulcan's life Star Trek: Discovery grants fans, the painting Spock owned and displayed aboard the Starship Enterprise in Star Trek VI now makes more sense than ever before.