How do I change a product variaton through an image field?
Try using Commerce Fancy Attributes along with Field Extractor Module

This module provides:


A formatter for reference fields
A views field for reference fields (called "Field extracted from entity referenced through $field")


This module uses field_view_field hook


  Returns a renderable array for the value of a single field in an
  entity.
  
  The resulting output is a fully themed field with label and multiple
  values.