Massive Spoilers for Season 1, much of it not behind spoiler blocks!
I haven't watched Season 2 (yet), so please no answers that are spoilers for that.
In the final showdown with Kilgrave ...
Jessica pretends to still be controlled by Kilgrave, but in fact is not.
She continues doing that whilst he mostly monologues at her. She answers questions honestly and lets Kilgrave assualt Trish. Then after a while she
reveals herself and snaps his neck.
There's no apparent hesitation or turmoil about whether to kill him.
Nor any apparent mental fight to overcome his control, given which she must have known immediately that she wasn't controlled.
So it seems like she was standing there for no reason.
Out-of-universe, it's obviously extending the audience tension, as to whether this is an upper- or a downer-ending, and getting to call back to the "I love you" codephrase, but is there any reasonable in-universe explanation for the grandstanding, rather than just walking straight up to him and punching his nose through the back of his skull?