One thing that you showed is that Poppy's in-world face is a lot like the one in the ad I showed--I assumed it had been "made up" for the ads.
But I have scrutinized the pics you posted, and I maintain that there are only two possibilities: It is the same face model altered slightly, or it is exactly the same model.
I really think it is exactly the same, as 1. The NPC has her neck extended, which makes her neck/chin line look different (I did think it was different, at first), and 2. Lighting can have a dramatic effect on how a model appears, for example, the lines on either side of the mouth appear deeper in the NPC, but I don't believe they actually are when comparing all of the pictures posted so far.
The eyebrows appear different in your pics--Poppy's appear more curved--but if you look at the pics I posted, Poppy's are exactly the same as the NPC below. Besides, even if they were different, eyebrows are part of the texture and not the facial model, which is what I am referring to.
This of course is of no import in the real world, but I honestly don't understand how this isn't obvious, lol. Is it just the conviction that Rockstar would never use such a character as a common NPC?