There really isn't anything noticeable beyond the change in the version display (version 1.2 to version 1.3) and it is likely that the update makes a few under the hood adjustments that improves performance.
For those not familiar with Creative Studio, it is available on all Nokia Lumia Windows Phones and is a basic photo editing app. You can take and edit photographs through Creative Studios, edit existing photos from your Pictures Hub and create panorama images. Creative Studios has special effects, filters and your basic editing tools (crop, contrast, exposure, etc.) that you can apply to your photos.
You can find Creative Studios on your Nokia Lumia Windows Phone from the Marketplace app under the Nokia Collection.
Thanks, ej lee, for the tip!