Why cut out the longing look?
To decide when or how the scene "ends" means deciding what the scene's about in the first place.
Padme talks a lot about what she used to do here growing up and Anakin listens to her-- but what's really happening? The scene is not about that, it's about what they're feeling and not saying.
She's talking about stuff to avoid awkward silence -- but she's sharing details of her past because she likes him and that's what people do when they like each other. Anakin listens, but his brooding manner cannot hide his feelings-- in fact it speaks as loudly as if he were using the words: "I'm really hot for you."
So when she finishes talking and turns to him the scene is about to turn-- the truth of the moment will become clear to the characters: love is in the air.
Is Anakin going to talk?
Will they kiss?
Neither of these are necessary for the scene to get to it's point. One shared look between these two will say everything that needs to be said. They have a mutual thing going.
But, as this is not an easy match, they are not likely to leap into action or even into talking about their feelings the moment they realize they might both like each other.
But once we know they are aware of their feelings, the next dramatic beat we care about is the point when the DO talk. So it's natural to cut from that moment on the balcony to the fireside -- PROVIDED the scene on the balcony goes far enough to demonstrate they are finally conscious of their feelings.
If, on the other hand, the balcony scene ends with Padme declaring she "can't give into this" then the fireside scene will become awkward -- why the costume change? Why the intimate setting? Why are they still talking about this? What happened in-between? It raises more questions than it settles.
If the balcony scene can end with the characters knowing they have something to talk about on the subject of love which they have not opened yet, then the fireside scene will play as it was always intended to, but never could. The costume and setting are Padme's attempt to go along with her feelings, but at the last moment she turns away because she knows logically that it's wrong.
None of these issues can be settled ahead of time if the fireside scene is to work.