Easter egg help - finding a particular one

[Nowhere Girl]

I have been trying to check the game's Easter eggs, but I can't find information on all of them. I know that there is such a screenshot in the game because someone posted it:

...but for the life of me, I have no idea how to get there! Does anyone perhaps know it?

[Tawmis]

I've beat the game once. I've only ever (I think) played it that one time, then again after I got it on GoG or whatever (but didn't finish it that time). I don't think in either of those I found any Easter Eggs.