>>1380567It might be a flashback, but it's probably just some instrumentality mindfuck.
Happens just before this.
Shinji and Asuka are having sex, but Shinji won't look at her. Asuka of course hates being ignored so she bugs out and starts beating him with a chair until Shinji snaps and starts choking her. Then of course, if you belive it to be a flashback, Asuka runs off and slits her wrists in the bathtub while Shinji gets it on with Kaworu.