I read it as her recognizing the guy who captured and tortured her and being afraid of Vader.
I mean, at that point they’ve already had a nice banquet together so she would be way beyond the point of just recognizing him. I’m sure she is afraid of Vader, but she also looks pissed. Like, she hates Vader.
Which would’ve made playing up her role more in ROTJ even better. Despite what his father has become, he still has love for him. Leia on the other hand doesn’t. When Vader says, “If you will not turn to the dark side, then perhaps she will” I think Leia totally would have, which makes Luke’s reaction and fury more compelling. People have talked about not seeing a reason why Luke would’ve turned, but I can easily see Leia wanting to kill Vader and being seduced by that power.
And that is a really interesting observation, Channel72! It is one of those things that retroactively has a little more subtext, even if that wasn’t the intention when it was filmed.
Another serendipitous thing in Empire is obviously Leia sensing Luke hanging underneath Cloud City. Clearly when they filmed it it was more about Luke calling out to Leia and Leia simply hearing it, but again, it retroactively becomes a hint toward Leia being “the other” Yoda referred to.”
Making Leia “the other” and going back to Tatooine were two decisions that I think make ROTJ arguably less interesting from a new worlds and new characters perspective, but both of those things were at least set up to an extent in Empire. Though Leia kissing Luke is the only thing that still makes the sibling thing kind of weird. If they had kept some of the other deleted scenes of them to, I don’t think they would’ve been able to make that retcon!