As you can see from this discussion Re: How do I print preview ZPL? seems there is no way to get a print preview through the driver. Zebra drivers don't really render a bitmap, but ZPL that the printer understands. Also drivers aren't bi-directional, so there is no way to get an image from the printer with it.
As an option you can programmatically substitute needed field values in ZPL code of your labels and do a print preview using the printer's webpage and resulted ZPL.
Software Engineer, Kutir Mobility
Posted on behalf of Zebra Technologies