Here's how you can see a larger preview of a file in the Get Info menu in OS X Mountain Lion. 1. Select the file. 2. Press Command + I on your keyboard (or select File then Get info from the file's menu in the menubar). 3. Go to the Preview tab. 4. You'll see a small preview of the file. 5. Double click the preview. 6. A larger preview will pop up on your screen.
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Use the Get Info window in Mac OS X | Daily Mac Tips