The central theme here is how memories and perception are entirely just fabrications of our minds. Consider hallucinations, or worse, Schizophrenia. To the person suffering from either of those, what they percieve, is absolutely real.
I've personally had multiple times where I've woken up and had visual, audial, and even touch-based hallucinations, or lingering feelings from the dream. I've heard people talk to me, I've felt them touch me, I've seen them in front of me.
To everyone else, these things are not real, but to me, they were entirely real. For the Droid, the Maid, the same is happening, but on a much more intense scale. Her actual "brain" has been implanted with non-existent data. That Toy Shop doesn't exist. But to her, it is entirely real. She cannot make it go away, just as you can't just "will" the sight of your hands to go away. They are there, you will perceive them, so long as you have the means to do so.
The Droid is just a robot, it can be modified, and the creator of the map even offers to delete the Toy Shop from her "brain". Her memories, her experiences, and everything that makes her, her, are all modifiable.
The Droid is not human, but she seems like it.
Humans can be modified in the same way, we just don't know the inner workings of our brain enough to manage to do it however.
Hopefully, this clears things up a bit, I rambled more than I wanted, but if you re-read, it should make sense.