She drags out the goodbye so leaving does not end it too soon
When a person actually wants to leave, the exit is simple. Bag zipped. Hug done. Door open.
A stretched goodbye comes loaded with extra tasks, most of them invented on the spot. She checks her phone but does not actually walk. She remembers one more question. She gets halfway to the door, then turns back with a remark that could easily have been said earlier. Her friends may already be outside, watching through the glass.
She is not confessing to anything. She is simply keeping the last few minutes from closing too neatly.
She lets him catch the look, then casts him as the bold one
The bold part is not always the look itself. Sometimes it is letting him catch her at it.
She glances away slowly, never quite fast enough to erase what happened. Then she makes him carry the awkward half. If he walks over, she might raise an eyebrow as if he kicked the whole thing off. She might smile at her friend, as though this sudden approach had been his idea all along.
That small reversal protects her. He has proof, but not quite enough proof to get lazy about it. He still has to make the call.
Even the strongest signal still leaves him some work to do
The clearest signals almost always leave one thing unfinished. She repeats the pass, holds the look, closes the distance, drags out the goodbye. What she does not do is spell out the whole route.
That is where a lot of men lock up. They want the sign to drop in like a notification, clean and impossible to misread. Real rooms are messier than that. A friend cuts in. A drink arrives. Someone glances at the group chat. The opening is there, and then it starts to shrink.
She has given him enough to notice. After that it is on him to read the room, take the risk, and cross the distance before the night moves along without him.