The GR allows you to shoot photos with several different effects and save them as JPEG's. As I prefer to shoot in RAW mode, I don't want to create my only file using a digital effect and save it as a JPEG.
However, the GR also allows you to develop your RAW files in-camera using the same effects, and the camera will save both your original RAW file and the new JPEG file.
Here's a quick example of developing a RAW file in the GR. The first image is my original RAW image shot in Chico, North Dakota looking south towards the northern entrance to Yellowstone Park.
After selecting the RAW image in review mode, hit the MENU button and select Raw Development in Playback mode. You'll be able to select a number of different effects and adjust parameters such as Contrast, Sharpness, Vignetting and other parameters depending on the effect you've chosen.
Effect: Black & White
Effect: B&W (TE) Sepia:
Effect: Positive Film
While I made very few adjustments to the standard parameters that the GR uses when developing RAW files, I think these images give you an idea of what's possible if you want to process your images in-camera.
Note: click on any image to see a larger file.