They were blurred out.
Now that video software is cheap and easy to use a person can re-edit anything. These actors were likely not extras since the storyline in that flashback had mostly main characters interacting at a Quartermaine party. I think that woman in the second picture was the originally Carly.
Is it right to change the past? Do these actors get paid when the footage is used? Do these actors get paid if they are pixelated or erased?