Are you playing with the cheat menu enabled? If so, you need to set variable enc = False, via the console or you won't be able to unlock them (at least most of them). You'll unlock these images as you progress through the game by completing quests. Some require specific actions like 'look at her feet', etc.
In the search box type "_happy" (without quotes) and enable wildcards (W button on the right side of the URM screen), then search and it should show you a list of various characters, just edit the value for the one needed. Can do the same for the drunk stat.
If you can wait a little, I'm planning to create a small mod that unlocks the bonus images and I can share it with you.
I have completed the whole Bella story, it has got nothing to do with what I asked because I sold him out at the beginning of the game and I could not work for him while I was completing Bella story.
