"Next, we need to choice an experience scale" - choice should be choose
"Select the MixedRealityCameraParent in the hierarchy and change the Transform -> Position -> Y to 0.8. This will move the camera to a natural eye level." - The image shows 0.0 for the Transform -> Position -> Y. It should show 0.8.
In 4. Environment Setup (VR)
"Next, we need to choice an experience scale" - choice should be choose
"Select the MixedRealityCameraParent in the hierarchy and change the Transform -> Position -> Y to 0.8. This will move the camera to a natural eye level." - The image shows 0.0 for the Transform -> Position -> Y. It should show 0.8.