Image Source: Disney Plus
Disney+'s Loki premiered on June 9, and there are already so many different moments to dissect, from tiny props to the end credits. However, one blink-and-you-miss-it scene in the first episode is really sending Marvel fans into theory overdrive. After a sit down with Mobius M. Mobius, Loki attempts to escape. Around the 33:55 mark, we see Loki standing in a hallway as a woman is escorted into the Time Variance Authority for seemingly disrupting the sacred timeline. While it could mean nothing, fans are convinced the woman is actually Peggy Carter. Not only does she bare a strikingly resemblance to actress Hayley Atwell, but she is also sporting a retro blue dress similar to the ones Peggy often wears. Though Atwell doesn't have a casting credit for the episode, it would be just like Marvel to place a huge Easter egg like this right under our noses.
Image Source: Everett Collection
If this is indeed Peggy Carter, what exactly does this mean for the MCU? Well, it could go two different ways. It's possible that this is the Peggy from the new timeline Steve Rogers seemingly creates when he goes back in time in Avengers: Endgame. As Ravonna Renslayer pointed out, everything the Avengers did in Avengers: Endgame was supposed to happen, so the TVA never interjected with their plans to go back in time. Seeing that Steve Rogers does return to his original timeline at the end of Endgame, it's possible that the TVA decided to take his alternate timeline Peggy to keep the sacred timeline in tact. So basically, Steve got to live out his life with Peggy like he wanted, but that timeline doesn't actually exist anymore.
Another possibility is that this is Marvel's way of setting up their new animated series What If...?, which literally explores what would happen if big moments from the MCU films played out differently. The new series, which will feature a handful of notable MCU stars including Atwell, will explore what would have happened if Peggy took the Super Soldier Serum instead of Steve Rogers. Perhaps this Loki scene is Marvel's way of setting up the upcoming series. What If...? is set to premiere in August, so we have a feeling we'll be finding out very soon.