The simpler explanation is that those five other people see you raising your arm. There are not five arms being raised but one arm seen from five different angles and distances.

You could say this is possible because God sees your arm raised from every possible angle and distance. Otherwise...?

Hi,
I'm thinking the effect is partially causation and partially correlation. There's six conceptions of Lambda , the actual state of Lambda, is none of them.
If you , 'your own conceptualization of Lambda' raise your arm, it does indeed change that which will be presented for consideration by the other viewers, but each perspective will be different. Their idea of what has happened only roughly correlates to the new actual state of Lambda. For instance , they cant see infrared effects of your motion.
I'm thinking your volition was indeed causal , its just not fixedly linked to the others perspectives.
The material effects of your volition are mediated by your physical arm. You clearly don't control their minds directly. And so I wouldn't describe their impressions as other aspects of 'you', an individual self conceptualizing itself as Lambda.
I don't find the existence of other minds as strange , as I do the fact that others view the world ,so differently from me . :)
I do like the way you presented the consideration though.

John I don't think that's correct. Consider the following two ontologies:

Ontology 1: 5 visual fields

Ontology 2: 5 visual fields + an independently existing human body

Ontology 1 is simpler...

In what sense is the human body independently existing from its visual field? What is left of a visual field if you remove the body which constitutes its point and angle of view, i.e. the properties which constitute the field?

Ontology 3: A field, within which innumerable bodies and visual fields, none of which exist independently of the field. Ontology 3 is simplest.