Portal: Hidden GLaDOS Camera Shy Voiceline 

This voiceline is normally not played when you get the Camera Shy achievement. However, there is a hidden dialogue counter that increments as you destroy every camera.
For some reason, destroying a camera while GLaDOS is speaking makes the game think that you "didn't" destroy the camera despite the camera physically destroyed by a portal.
This is what happens when you destroy the last camera.
This is not modded in any way, you can actually get this voiceline by legitimate means.
#portal