Spoiler warning: spoilers for Avengers: Endgame ahead.
While Natalie Portman’s Doctor Jane Foster made a cameo in Avengers: Endgame, the actress didn’t actually shoot any new footage for the appearance.
Reported by Entertainment Weekly, directors Anthony and Joe Russo explained the only new content Portman provided for the film was a quick piece of voiceover work. Anthony said “All she did new for this movie was…”
“The voice,” said Joe.
“A little bit of voice-over when she’s talking in the distance, that’s it,” finished Anthony.
The scene in question takes place on Asgard in 2013 and focuses on Jane in the distance thanking a group of Asgardians for taking care of her, though the newly provided piece of vocal work itself is relatively hard to distinguish, and largely just lends to the overall believability of the scene.
Source: IGN.com Endgame Included Unused Thor 2 Footage