Resource interpreted as Document but transferred with MIME type image/jpeg:

I’m working on a site and I’m getting a weird error with a lightbox. When I click an image in the following gallery

http://www.balletmall.eu/marcocappalungadotcom/gallerie/gallerie-matrimoni-2/

It gives me this error

Resource interpreted as Document but transferred with MIME type image/jpeg: "http://www.balletmall.eu/marcocappalungadotcom/wp-content/uploads/2013/10/005.jpg".

Then when I click a different image it works, what would be causing that first error? Any help would be massively useful.

Thank you