Galadriel & Sauron Dynamic is an Exercise in Red Flags Spotting
Well, not their dynamics as a whole.
For those who did not think that Halbrand was Sauron from his first scene, it was not a matter of failing to see, but of refusing to see the obvious, and on the other hand it was crystal clear that The Rings of Power 's version of Galadriel is the sort of person who makes the disguised Sauron seem reasonable by contrast.
We're talking about their final dialogue, when Galadriel finally figures out that something is wrong with Halbrand, starting with the words "I have been awake since before the breaking of the first silence".
In this scene, Halbrand goes through a series of arguments and styles of persuasion, trying to convince Galadriel to join him, looking for any opening, any way in.
Not only is this in itself a good indication that his intentions are anything but good, regardless of what he professes, but the nature of each of his specific approaches also raises massive red flags.
First, he tries to subdue her with a happy illusion, pretending to be her brother. When that doesn't work, he moves on to more or less literal seduction, first trying to pretend that all his lies by omission or implication don't count, then exploiting her isolation while trying to use her hubris to increase that isolation ("All others look on you with doubt. I alone can see your greatness"), and then even promising to share power while throwing in a not-so-veiled "you can fix me" message.
When that doesn't work either, and he becomes increasingly desperate, he resorts to claiming that Galadriel has no choice but to do what he wants, and finally to outright blackmail.
And as if that were not enough, the scenery also speaks for Sauron.
At first he gives Galadriel the illusion that she can walk away in the wide open, but as soon as she takes a step away from him, he locks her up on a tiny raft.
And whenever he doesn't get his way, his composure cracks and he flies into a rage, recovering quickly the first time, and screaming again when all else fails. All in all, the whole scene is a showcase of abusive relationship approaches.
Not that this gallery of red flags stopped the shippers anyway.