I considered other labeled axes but used the original (x) in the sketch because original board orientation is unknown (to me). I thought, "maybe it is not for left/right of a vertical object on a horizontal plane, but left/right of a vertical object on a vertical plane." There is a lot I do not know, and tried to make the sketch work.
Haha, I think of it as a horizontal object on a horizontal plane and is reporting positive "above" and negative "below" values.
Your sim works fine and was useful. And easier than finding the MPU6050 modules that are in the lab somewhere.
a7