Warning! Spoilers ahead of Shang-Chi and the Legend of the Ten Rings.
Captain Marvel (Brie Larson) cameos in Shang-Chi and the Legend of the Ten Rings sporting a brand new hairstyle — what brought on this change in appearance? Director Destin Cretton delivers a win for Marvel Studios via the Simu Liu-led blockbuster. As the MCU's first exclusive theater release since 2019, the film was both a critical and box office success. It also sets up Shang-Chi's place in the MCU moving forward.
As with most Marvel Studios' origins stories, Shang-Chi and the Legend of the Ten Rings has a contained narrative, focusing on introducing the titular character and his pocket of the franchise. From the get-go, however, there was already an expectation that the blockbuster will have some ties to be bigger MCU just by the involvement of the Ten Rings, not to mention the arrival of the real Mandarin named Wenwu (Tony Leung). Aside from that, there are also cameos that have been revealed through the film's marketing campaign such as Wong (Benedict Wong) and Abomination (Tim Roth). That's not all, though, as Shang-Chi and the Legend of the Ten Rings saved its best guest stars for its after-credits scene.
The film's first stinger directly connects to its ending. After Wong summoned Shang-Chi and Katy (Akwafina), they're led to what appears to be the Sanctum Sanctorum. There, they investigate the origins of the Ten Rings as their powers were felt all the way to Kamar-Taj when Shang-Chi first used them in Ta-Lo. Apparently, the trio was joined by Bruce Banner (Mark Ruffalo) and Captain Marvel — both looking different from the last time they were in Avengers: Endgame. Instead of being Smart Hulk, Banner is back to his human form. He wears an arm sling, indicating that the meeting takes place not long after the defeat of Thanos (Josh Brolin) since he's still nursing the injury he got from the reverse snap. This makes Carol Danvers' appearance much more intriguing. Instead of the pixie cut that she had in the 2019 Russo Brothers blockbuster, she's sporting her blonde locks significantly longer. This poses the question of what brought on this change.
It's worth noting that Captain Marvel's costume is still the same, only her hair is different in the Shang-Chi and the Legend of the Ten Rings post-credits scene. Considering the timeline in terms of Marvel Studios' production, it's safe to assume that this will be her look in The Marvels — at least when the film picks up. Both producer Jonathan Schwartz and Cretton explained that while the idea for the stinger came up early in the process, they weren't able to shoot the scene until reshoots due to various factors, including scheduling conflicts. Since Larson was in the process of gearing up for The Marvels leading up to Shang-Chi and the Legend of the Ten Rings, it was more efficient to shoot the tag sequence during the same day that she was doing some work for her own film. Unlike Ruffalo, who was in civilian clothes while reprising his role as Bruce Banner, Larson needed to be in full Captain Marvel costume, which means more work for her to just film a brief scene.
Narrative-wise, Marvel Studios still needs to explain how Danvers suddenly has long hair in the Shang-Chi and the Legend of the Ten Rings. Perhaps they will provide one in future projects like The Marvels. But considering how the coronavirus pandemic made film productions much trickier, many would highly likely be understanding if there's no canon justification for it.
