Example to test: .ppt shows up like the image for me.
black-chart.zip (application/zip), 130.27 KB, created by jonnjones on 2012-09-02 16:05:33 UTC
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Creator: jonnjones
Created: 2012-09-02 16:05:33 UTC
Size: 130.27 KB

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Attachments on bug 48438: 66496