,Why is the same localPosition for two objects with the same parents showing up differently?

I'm fairly new to unity stuck on a problem to do with localPosition vs 'real world' position.

To illustrate my problem, I have:

• Two anchor models, with the same position and rotation

• Two cubes: respective children of the two anchor models

• Cubes have the same localPosition (0,0,1)

Why are the cubes in completely different places? (see image)

I would have thought that if the two parents had the same position & rotation, then their children with the same localPosition would end up in the same position too.

here's the code I use to place the cubes:

 // place a cube 1m forward of the 2nd anchor
 var secondAnchorCube = Instantiate(CubePrefab, secondAnchor.transform, false);
 secondAnchorCube.transform.localPosition = new Vector3(0, 0, 1);
 
 // place a cube 1m forward of the 2nd model
 var secondModelCube = Instantiate(CubePrefab, secondModel.transform, false);
 secondModelCube.transform.localPosition = new Vector3(0, 0, 1);