Does attaching aluminium foil to the inside of double glazed windows cause mildew?

I have attached aluminium foil to the inside of my double glazing, with the reflective side facing out, and my mother thinks it will cause mildew. I have done some preliminary research and found mildew will occur regardless of the foil being there, but are her concerns warranted or is she just trying to get me to take it down due to the fact it looks unsightly?