In the trial version, any image you save will have a watermark or a color cast applied. A legitimate key removes this entirely, giving you clean, professional output.
Using the free trial is fine for testing, but running a business or managing a large photo library requires the full version. Here is what a valid Photoworks Key unlocks: photoworks key
If you are running a legacy version of SolidWorks (e.g., SW 2014 or older) and trying to use a Photoworks key: In the trial version, any image you save