In the latest trailer for Loki, there's a split-second shot that has everyone guessing. Loki is seen sitting in a strange purple landscape with a short-haired blond woman in a black costume. The big question is who that woman is: is she Natasha Romanoff in some alternate timeline or form, or is she Lady Loki, a comics character who hasn't appeared in the Marvel Cinematic Universe yet?
Right now, the evidence seems to be leaning toward the latter. Loki has a blond woman with a short haircut in its cast who looks vaguely similar to Scarlett Johansson from a distance: Sophia Di Martino, whose role in the show has not yet been revealed, suggesting that it's a spoilery secret. The trailer talks about "variants" of characters, including Loki himself, and seems to imply the existence of many more timelines, which was first teased in Avengers: Endgame. One variant in the comics is Lady Loki. If the show is pulling us into the multiverse, which is a popular fan theory, then the presence of Lady Loki would make total sense.
Lady Loki notably appears in a post-Ragnarok comics arc in which Loki brings together surviving Asgardians and tricks Thor into restoring them all — Loki included — to full power. As a result, Loki is "reborn" in a female body and swears to be done with schemes to take over the throne of Asgard. In some ways, the presence of Lady Loki would be a perfect fit for this show. After all, the Loki we see in the show is not the one who survived Thor: Ragnarok and died at the hands of Thanos; this is an alternate timeline's Loki who escaped after the Battle of New York in 2012 and hasn't undergone the same character development. We're already seeing one variant of Loki; what's one more?
We won't really know what's going on until after Loki's June 11 premiere date, but in the meantime, theorize away!