You have a javascript error, you can see it in the js console when it says Uncaught TypeError: Object #<Object> has no method 'describe'
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In production mode the file is concatenated so when you have an error like this, the code below it won't execute at all. So this way Posts isn't defined.
You still have the error locally, but the files aren't concatenated so an error in one will not affect the other files and the error wouldn't be that apparent.
You would have to fix your other error for the rest of the code to run.
Nice site btw.