Context of range inside partial points to collection being iterated

Inside my partial I am going over a map, that I got from .Site.Data.images ( a yaml file ).
The context inside that range however, points to the dictionary that I passed in when calling the partial from the parent partial.

I would expect . to be set to the current item during the iteration of .images.

parent.html

{{- $img := partial "functions/image.html" (dict "filename" $path "images" $.Site.Data.images ) }}

image.html

{{ range .images }}
  {{ . }}  <-- why is this not set to the current item of the range .images? -->
{{ end }}

Give us example data of what $.Site.Data.images should contain. And/or post an example YAML file.