Dear me,

If you look the tranmission from your Firefox, you will see that mimetype send by firefox is bad (with firebug for instance on the upload POST request). In your own case, you see this “application/binary”. Nuxeo don't manage this mimetype, so no icon association to powerpoint, no converter availlable to transform from this mimetype to pdf or html (for preview).

You can enjoy to remove this bad association between Powerpoint (ahhh Lovely), and “application/binary” in mimeTypes.rdf somewhere in your application data (for windows) or somewhere else for other OS (I let you find the location on Google).

Have fun !