Setting content type on file isn't working

I've modified this sample to include the content type so the file(s) are understandable by a browser, but this doesn't set the content type:

var options = { contentSettings: { contentType: 'application/pdf'}}; fileService.createFileFromLocalFile(shareName, directoryName, fileName, imageToUpload, options, function (error) { if (error) { callback(error); } else {

This doesn't work with a PDF and it doesn't work with an image (image/png). How can I set the content type on an uploaded file so the file is accessible from my website?

[robinsh]

@seguler Can you comment?